Boos sit comfortably in the middle of the spookiness levels. While they are cartoonish and round, they do radiate anger, which sets them safely in the 5 for spook.

Danger can be varied. Some boos will slowly approach and halt when looked at, only to begin again when Mario looks away. Others will be paired with a group and follow repeated patterns of movement, serving more as an obstacle than an enemy. Despite these weak strategies of attack, they are often invulnerable to all but the Star power-up, keeping them around a 5 for danger as well.

It is unclear exactly what sort of race these spectres arise from, however it is known they create societies with monarchical leadership indicated by the crown of their king, much like the human characters such as Princess Peach. Comparing a boo to Mario shows they undergo many changes. Their original form is lost and their features are elongated an malleable. 7/10 for transformation.

Boos are an extremely simple name to go by. It fits well, knowing ghosts to be associated with the exclamation, but is also rather silly and simple. 3/10.

Dry Bones are the skeletal variant of the Koopa Troopas. While they may look more fragile, they are able to reform time and time again after their bones collapse. Their dead yellow eyes and cracked shells have some amount of spook, however they are also rather passive looking and acting, and so will receive a 3 in spook.

Danger is a 4. While they possess strong endurance to normal blows, these husks can be defeated through freezing, followed by throwing their frozen bodies.

Transform is going to be a 2 as it is a clear transition from a living Koopa Troopa, however they also gain the glowing yellow eyes.

The name is (as pointed out by my hero Brian David Gilbert) somewhat disturbing. If there are "dry" forms of us, are we the "wet" forms of them? An uncomfortable thought no doubt. Why chose "dry" as the adjective to denote undeath? Lack of organs? 4/10.

Stretches are strange Boos that arise and slide along the ground. They will be raised 1 in spook from the basic Boos for the odd plunger legs they have.

The danger, due to the more limited ability to move, will bring the Stretches down one from the basic Boos.

Transform will be raised along with the spook due to the plunger legs.

The name is strangely familiar. I am reminded of Stretch from Casper, who was given a 2 and so these boys will be matched.

Honen, which are different from the normal bone fish used in the majority of the Mario games, exist only in Super Mario Land. They look very surprised of their situation which is a little disturbing, and will be given a 6/10 for spook.

The danger is hard to calculate as I have never played Super Mario Land, but they are described as "easily defeatable" by the Super Mario Wiki, and so will be given a 2.

Transform is easy to determine because they are the undead variant of the Torian. I would say they are a 1, simply the bones of their previous self.

Finally the name Honen sounds somewhat intriguing, but beyond that is meaningless to me. 3/10.

The only other undead enemy in Super Mario Land, Pionpi is based off of the Jiangshi of chinese folk lore, which are apparently these vampire/zombie like undead that hop around in the night. Little spooky, not too spooky. 4/10.

Pionpi works similarly to Dry Bones in that when hopped on they fall apart and rebuild after a moment. However, Pionpi also tries to jump on Mario. This will give Pionpi a 5 rather than a 4 like Dry Bones.

Transform looks to be from a normal human, and turns the skin grey, and the eyes seem sunken. 2/10.

Pionpi is a pretty silly and meaningless name in English, however comes from the mimetic use of jumping, and a play on the word Jianshi's pronunciation in Japanese. 2/10.

Spook - 6. Boo but big.

Danger - 6. Boo but big.

Transform - 7. Still boo but big.

Name - 2. Big Boo? Lame.

Spook is about a 4. They usually look like turtles with glowing eyes, which is not so spooky. Sometimes they have spikes but even then they aren't that menacing.

Danger is maybe a 4? They reassemble much like the Dry Bones, but are half the size. To make up for this, they occasionally have retractable spikes, but these two attributes, the shortness and the spikiness, balance out and remain at the same level of the Dry Bones.

Transform is more easily calculable then most because we have conclusive evidence that a Bony Beetle is just an undead Buzzy Beetle. Skeleton, plus yellow eyes, plus spikes, 3/10.

Bony Beetle is a 1/10. Bony is lame as a prefix adjective, and this is clearly a turtle not a beetle.

The spook of a Boo Block relies on its ability to hide in plain sight, before becoming the more common Boo shape. As such, the spook will be an 8. Having the floor suddenly disappear beneath you and become a large ball that laughs in your face sounds pretty dang scary.

Danger is a 6, a stronger version of a Boo. Because they seem to be the same size as a normal Boo, I would say a Big Boo is on par with the Boo Block.

Transform is an 8. The color is negligible, ghosts are not often the color of the person who passes anyway, but the ability to become a block puts them a step above a normal Boo.

Boo Block is the name on the Wiki, and seems to be the primary name for this enemy, however, the better name, Block Boo, is also listed. 2/10. Its a bad name, but is at least accurate, unlike the Bony Beetle.

Boo Buddies exist to insult me personally. These circling Boos are distinct from casual Boos as they are linked to their group. Meaning my original description of boos occasionally being paired is a LIE. The spook of Boo Buddies will remain a 5. While their are now many, they also do not approach the player, instead circling menacingly.

The danger is lower than a Boo due to the fact they do not act aggressively. They circling harmlessly, and serve more as a obstacle than an enemy. 3/10 danger.

Transform is the same as a Boo. 7/10. Just lots of Boos.

Boo Buddies is so friendly. It sounds like the title of a children's show. 3/10. Still better than Boo Block.

Spook of the Boo Buddy Snake is a 7. These Boos bounce diagonally about, and are nearly invulnerable. Their demeaning and ghastly faces disturb and strike fear into their prey.

The danger of a Boo Buddy Snake will remain at a 5, the basic Boos move more directly at the player, but the Boo Buddy Snake is larger and more erratic, at the cost of no direct attack.

Transform is still a 7 like a Boo.

Boo Buddy Snake is a 3 for the name. Buddy Snake is uncomfortably close to Human Centipede and that disturbs me. But Boo Buddy is still pretty soft.

An even larger horde than the Boo Buddies, these Boos will swap between transparent and opaque, charging at the player as they do so. Their spook will sit at a 6, the randomness of the charging Boos bring quite daunting.

The danger will also be a 6, as their direct charge serves to be quite dangerous, along with no way to harm them.

Transform is still 7, lots of Boos.

The name will be a 5. The Boo Crew has a nice sound to it. Mob boss-esque.

Disappearing Boo Buddies are very similar to the Boo Crew however rather than going transparent, they simply disappear and reappear elsewhere. Their spook will remain constant, as anticipation helps the Crew, while sudden danger helps these Buddies.

Danger will increase to a 7, as the immediacy and lack of warning for these Boos trumps the slight warning given by the Crew.

Transformation still sits at a 7. Because of Boos.

The name is sort of long and lacks any imagination. 3/10.

Eeries are ghost dinosaurs that wobble or shoot across the screen in order to damage the player. However they look pretty cute. 1/10 spook.

Their danger is going to be a 6 to raise them above Boos, however this is only because they never suffer the problem of freezing when looked at, they work similarly in every respect, flying through blocks and only being defeated by the star power.

Transformation is going to be a 4. They seem to be ghosts of baby Yoshis, having a similar eye and body shape.

The name will be a 6. Simplicity with a spooky theme is always good.

Spook is hefty. The skeletal fish body is something we have seen before, but this is the more classic and well known look. The Fishbone is a near constant in contemporary 2D Mario games and always spooks me. Its large orbitals that shift to a red when charging at the player. 7/10.

Danger is mid class. While they are effective attackers, they do fall apart quite easily with the smallest amount of resistance. 5/10.

The transform seems to be around a 2, the Fishbone assumed to be the skeletal reincarnation of a Cheep Cheep. it gains an additional point for the color changing eyes.

Fishbone is pretty weak as a name. 2/10. Fish. Bone. Lame.

The Fishin Boo is the ghost of a Lakitu, their cloud now faceless, and pursues the player with a fiery fishing rod. While it is not the spookiest, there is something disturbing about the now faceless cloud, ridden by the ghost of an enemy. 6/10 spook.

The danger of a Fishing Boo is in its ability to disrupt the flow of moving, creating a space that follows you, and deals damage. They also are invulnerable. 5/10.

Transform is around a 3? The Lakitu is very similar to its ghost form, however they lose the shell and become a more ghostly shape.

The name is pretty underwhelming. This Boo also looks much different from normal Boos, confirming that "Boo" is just a name for a ghost in Mario, not the specific ghost type. 2/10.

-Another skeletal fish, this one in Super Mario Land 2: 6 Golden Coins. While this art clearly shows a very aggressive look, in-game they look almost identical to the Fishbones. 7/10.

Danger will be increased by 1 as they move in a V shape rather than directly at the player, making them a little less predictable. 6/10.

Transform will remain the same as they are visually similar to the Fishbone and are said to be a cheep-cheep skeleton as well, the eyes still being a level above 1. 2/10.

The name is pronounced Hoo-en-bon. But I look at it and see Honeybone. Which is a great name. 5/10.

The best Mario enemy? J-son not only is visually similar to the iconic horror killer, but also named after him. Spook will be a 6. The fact they are Goomba shaped kills the scariness by quite a bit.

They are literally Goombas in function so they will receive a 1/10 for danger. They will walk off an edge if it sat in front of them.

Transform could be considered to come from a Goomba because they act that wat, so the red eyes are our only real difference we cans see. 2/10.

J-Son is hilarious. 8/10.

Look at this cutie. Kurokyura is such a little vampire baby. This boy looks so adorable. Spook is a 1. I want to cradle this little vampire baby in my arms and feed him bananas.

Kurokyura shoots bats, but can be stomped on like most enemies. 4/10 for danger.

Is this supposed to be a normal man like Mario and Luigi? Transform would be around a 4 then. The face looks a bit rounder and open, and the hands are very clubby, but beyond that this boy looks pretty normal.

Kurokyura comes from the Japanese name for Dracula, being Dorakyura, and Kuro meaning black. Black Dracula. Uh? Maybe a 4/10.

Skeleton Bee! What a scary looking dude! He looks pure evil. 6/10 spook.

Danger is a 5/10. Flies around slowly but is tougher than a usual bee.

Transform can be found due to a normal bee existing. The only real difference is the skull head, 2/10.

Name is wack as heck. 2/10. Skeleton Bee. Its not even a full skeleton. Skull Bee would be better.

Terekuribo is a Goomba Boo. They cannot be stomped, but still move like a Goomba. Spook is a 3.

Danger is a 4. Moves like a Goomba but can't be squashed.

Transform is a 3? Just no legs.

Name Terekuribo means pretty much nothing to English eyes like mine, but means Goomba Boo in Japanese. 3/10.

Yarikuri Obake are the only undead to appear in Wario Land: Super Mario Land 3. These round, spear wielding enemies look pretty soft and fluffy, but with an intimidating aura. 4/10 spook.

The danger of these ghosts is that of the basic boo, as they act in the same way, becoming shy when looked at, and pursuing when not. 5/10.

The transform will be a 4, no legs AND they change color.

Yarikuri Obake is just Pirate Goom Ghost in English, referring to the enemy they come from. Despite that it sounds very cool. 5/10.

Miira's are mummies. Pretty much as close to a basic mummy as one can get. So they get a 6 in spook.

The danger is not anymore than a normal Goomba. 2/10.

The transform is hard to determine but lets just say it is a humanoid figure like Mario that becomes the Miira, meaning it will remain a 3/10 like the basic Mummy.

Miira is not intimidating. It sounds like a cat's name. And it just means mummy in Japanese. 3/10.

Spook is maybe a 3? This lil skull boy is a cutie I love me a good boney.

Danger is a 4? Boney throws bones. But he doesn't move.

Transform is a 1 just bone.

Name is a LIE. This is not a skeleton. This is a skull. 1/10.

These Boos are honestly horrifying. I hate how they look. Being blindfolded always scares me. The weird pink ears look so out of place, the teeth are too much. Very creepy. 9/10.

The danger is... different? They can't see, so they go toward sounds. Like picking up coins. A 3? Maybe?

Transform will go up by 1 because of the disturbing ears and teeth. 8/10.

The name is going to be a 2. Blindfold Boo is one of those super obvious names that ruin it.

Boo Balloon is a Boo shaped like a Balloon. Shocker. They float around like balloons and slowly inflate when hit. 4/10 spook.

Danger is maybe a 2? They float around like a balloon not super intimidating or dangerous.

Transform is confusing. Is this a balloon that has been reincarnated? Is this a boo disguised as a balloon? I like to think of it as a now living balloon. In which case it is a 5 for transform.

The name is garbage 2/10 once again.

These guys are pretty spooky. Going from a low-key blob to a stretched out spooker is decently scary. 6/10.

Danger is decent as well. Invincible to most attacks, quick movement, and damaging to Yoshi whenever touched. 6/10.

Transform is tough to say. They share many design aspects with normal boos, the white, the large tongues, the scattered teeth, so I think it is fair to associate them with the same baseline, however with multiple forms, and more exaggerated features, I would bump up the Boo Blah to and 8 in transform.

Boo Blah is somewhat charming to me. Boo is just a silly non-word in its own right, so adding Blah to the end of it feels somewhat self aware and funny. 5/10.

Spook is a 4. These are Boos with the Shy Guy mask on. The mask is less scary than the Boo face in my opinion. Shy Guys have always been very cute to me.

Danger is a 2. Can be eaten by Yoshi and turned into eggs, or stomped on. Yoshi easily takes these boys out.

Transform will be on the same level of a basic Boo, as I don't think wearing a mask can constitute as a transformation. 7/10.

The name does not work in the same way as Boo Blah. This is clearly just a combination of the name Shy Guy and Boo. Which does not work in this format. 1/10.

Caged Ghosts rely on their size for most of their spook. Being large imposing figures brings with it a fair amount of spookiness. 5/10.

Danger is moderate at best. While damaging to the touch, they do not move beyond their limited space, only throwing smaller enemies at the player. 4/10.

Transform will be considered 1 more than a basic Boo, clearly sharing design aspects from them, however made large rectangular shapes. 8/10.

Caged Ghost is a confusing name. I guess they are caged in a way. But the name is a little misleading. They aren't in a physical cage, instead the limits of their own size is their cage. I guess, in a way, we are all caged then. Limited to what we can physically accomplish, no matter our dreams or aspirations. 3/10.

Dangling Ghosts are very similar to Caged Ghosts, however have no mouth, which I think reduces their spook factor quite a bit. 3/10.

Danger is 5/10. These guys will actually swing at the player to hit them. A step up from the Caged cousins.

Transform will also be increased to a 9. this droplet shape with no mouth is definitely a step up from rectangle.

Name is more accurate this time. Less existential. 4/10.

Pack creatures that will zoom at the player, these skeletons are fairly cute and are quite small. 2/10.

Danger is also minimal. Short little things easily defeated, and with the sole purpose of running head on to the player. 3/10.

Transform can be calculated as non skeleton Goonies exist. They are simply the skeleton of a Goonie with no real changes. 1/10.

The name is a mouthful. 2 Prefixes is a lot, and usually needs to be made worth their use. Flightless does not fit that criteria. We understand they are flightless. When I hear the name Goonie, I do not think wings, and I believe most would concur with this. 2/10 for this long name.

Spook is a 3. These guys have some spooky skeletal/ghostly traits, but are also pretty cute and soft looking.

Danger is a 3 as well. They grab onto Yoshi and reverse movement, but can be eaten before hand, or ground-pounded off after the fact.

Transform is hard to determine. They are closest in shape to Shy-Guys, but I wouldn't say it is a definitive connection. a 5 for transformation, both to stick with a middle ground, as well as their difference from Shy-Guys.

Grim Leecher is a cute name. It works with how they function, latching onto Yoshi, and with their design, looking like tiny Grim Reapers. 7/10.

Relay Heiho are a variant of Boo Guys that pass along bombs to drop on Yoshi. The spook will be the same as they look identical to Boo Guys. 4/10

The danger will increase by 1 to compensate for their bombs. 3/10.

Transform will remain at a 7 as they are the same as normal Boo Guys.

The name is actually kinda interesting. They remain Heiho, the Japanese name for Shy-Guys. I like it better. Relay Heiho is a 6/10.

These ones fly! Spook will go up 1 as flying skeletons look horrifying. 4/10

Danger will go up by 2 as the flight increases their size and aggression. 5/10.

Transform will remain 1 as they are just skeletons of Goonies. 1/10

A little bit better of a name. 3/10.

Look at this guy! A nightmare! 10/10 spook! Skeleton pirate crocodile! I love him!

They fly, and are equip with a scimitar. Pretty dangerous! 6/10.

Transform is easy because they are designated as Kremlings. They are almost just skeletons, but have a glowing eye, and they fly. 3/10.

The name is a little weak. Kackle like cackle. However cackling is quite the skeletal word. 4/10.

Kloaks are interesting, being possessed... coats. The build of the coat is spooky with the skull buttons and uncomfortable color palette. 7/10. They apparently laugh when summoning enemies which bumps them up a bit.

Danger is going to be a 4. They basically just summon other enemies which is a personal pet peave of mine. Enemies should not exist to summon other enemies. Thats lame. 4/10.

Transform will be a 2. It is a possession that, in theory, only changes the eyes in the middle of the coat. 2/10.

The name is dumb. It isn't even a cloak. Its a coat. 1/10.

Doppels are these strange alien ghosts in Super Mario RPG. Green, almost robotic looking, these guys are quite a unique style of undead. 7/10 spook.

Danger is going to be a 5. While they are quick and dangerous, they seem to be fairly simple in their abilities.

The transform is 7? A humanoid shape, but with some strange appendages, colors, and lines.

The name is reminiscent of the word Doppelganger, which is something we have seen before in undead. Doppel on its own feels quite innocent however, and sort of cutesy. 3/10.

Boo Guy plus a scythe. 5/10 spook.

Danger is, well, a Boo Guy with a scythe. 4/10 danger.

Transform is a Boo Guy with a scythe. Remains 7/10 transform.

The name is the only thing unique about this character, and it is somewhat disappointing from a fear factor. Glum is a pretty silly word, but Reaper has some weight. 5/10 name.

Scroll up. 5/10

Less dangerous than Glum Reapers. 3/10.

Scroll up. 7/10.

Greaper is honestly a little bit better than the Glum Reaper. 6/10.

I love this little fella. Their funny little face, their raggedy clothes, their impeccable lantern holding, what a legend. They give me small child vibes like Sam from Trick R' Treat. 8/10 spook.

Danger is a 5. They like scratching people, but seem relatively mundane.

Transform is difficult to determine as they are completely covered, but I would suspect they are a rather simple undead beneath the clothes, and give them a 3/10.

The name is confusing. Hobgoblins are often goblin like creatures in my experience, but these fellas are not goblin like at all. 4/10? Only because of my love of goblins.

These enemies are strange. They are referred to as Lil Boos in all other game versions except for the American version, where they are referred to as The Big Boo, as they are more powerful than normal Boos. Their spook is the same though. 5/10.

Because they are more powerful they will get an increase in danger by 1. 6/10.

Transform is the same, 7/10.

Name is weak either way. 2/10.

Mastadooms are skeletal mammoths with incredible strength. Lifeless eyes, submerged in the water, these are extremely spooky in theory, but are rounded and cartoonish in practice. 5/10 spook.

Danger will be a 7/10. They possess extreme strength and team destroying blasts, but are not quite on the level of mind boggling power.

The transform will be a 2. This is meant to be a mammoth, but the eyes are clearly more then empty holes. 2/10.

This is a great name! Mastadoom sounds both like a Master of Doom, and a Mastodon. 9/10.

Reachers are quite sad looking. Their little sharp claws and teeth add a little spook, but are mostly docile looking. 4/10.

Danger is going to be a 5. They throw bones and stretch their arms but aren't wildly powerful. 5/10.

Transform is hard to tell, but we will say a 2. Skeletons with fancy eyes usually get a 2/10.

The name is just okay. Probably another 4/10. Reacher isn't horrible, but not overly spooky or cool.

Shadows are black Doppels. The color scheme is spookier here for me so they will receive a 8/10.

Danger seems to be lower than the Doppels, so 4/10 for them.

Transform will also be one lower because black is a less strange color for a ghost than green. 6/10.

The name is lacking any creativity at all, and doesn't even make much sense for the design, besides being black. 2/10.

Strawheads are weaker, rarer variants to Hobgoblins, with unique scarecrow abilities. Their color pallet looks a bit spookier and darker, so they will get a 9/10.

Danger will drop substantially. Their scarecrow abilities are quite weak, and they deal little damage. 2/10.

Transform will remain the same as their Hobgoblin cousins at a 3/10.

The name will be a 6. Strawhead sounds like a horror villain that would stuff bodies with straw or something. I quite like it. 6/10.

Vomers are the Dry Bones of Super Mario RPG. They are rounded more, and have a lumpier back shell. 4/10 spook I think.

Danger is maybe a 5? They are stronger than a normal Dry Bones, but only by a little.

Transform will be a 3 because of their slightly unusual changes from a Koopa. 3/10.

The name Vomer is interesting. The layman might assume that this would be associated with the idea of vomit, a common idea with undead, however this is not true in this case, and Vomers have no vomit based attacks. Instead, they are named after a bone in the nose. Which is interesting, and keeps it from being a bad name. 6/10.

Grindels are described as "mummified Thwomps", and as such I will consider undead. They are quite horrifying with their large grins (hence the name) and I will give them a 7/10 for spook.

The danger is not very high, slowly rising and dropping, but they are invulnerable. 3/10 danger.

Transform will be a 3, the eyes and mouth changing drastically, along with being wrapped in linen.

The name is actually pretty okay. 5/10. Grinning guy can be a Grindel.

Snufits are boo shaped and so we will assume have some ghostness to them. Their spook is about a 6. Their lifeless masks make up most of their body which I find to be a rather spooky aesthetic. 6/10.

The danger will be a 4. They float around and shoot some bullets they balloon up first so its not super fast, and can just be hopped on. 4/10.

Transform will be from a Snifit, which goes from having feet and arms, to not. 2/10 transform.

The name is sort of funny. Snuff it means to die. That is cool. 5/10.

So this Boo is a blue mouthed Boo followed by tiny blue mouthed Boos. 6 spook because Boos but more. 6/10.

Danger is a 6 as well? Boos but more. 6/10.

Transform will be the same, the mouth is just blue its not worth another point.7/10.

Name is a lie! The "Big" Boo is a normal sized Boo, while the "Little" are little. 2/10 for liars.

OH HELL YEAH BABY. BONE DRAGON. Spook is an 8. Very spooky but somewhat dulled by the brontosaurus herbivore look. 8/10.

Danger is not very high. Stationary and more of a wall than an enemy. 2/10.

Transform is a 1. Skeleton of a thing.

BONE DRAGON. Eh. 4/10.

"Ghosts". They are only being included because they are literally called ghosts. I am very unsure of their undeadedness. However, they do look like screaming snakes and that is pretty spooky. 8/10.

Danger is hard to determine. They exist more as a mount for baby Bowser. They are invincible, and can fly. Maybe a 5/10?

Transform is undeterminable. They are a ghost, but of what? I have no idea. A man? This would be a 9. I guess we will go with a 9? 9/10.

Name is lame. Its just ghost? 6/10 for basic ghost.