Fishman

Great White

Your fearsome presence can make even the most courageous of opponents weak in the knees. As a bonus action you may unleash your full ferocious aura. Any enemies you choose within 15 ft of you must make a DC 8 + Prof Bonus + Charisma Mod, Wisdom Saving Throw. On a failure, they must use their full movement speed to move away from you as far as they can. A creature that has successfully saved against this effect becomes immune to it for the encounter.

Sawtooth

Your nose is a weapon in its own right. It is treated as a natural or melee weapon with which you are proficient and shares the same damage and properties as a rapier. A number of times equal to half your proficiency bonus rounded up you may make an attack with your nose as a reaction to being hit by a melee attack. This feature regains all uses on a short rest.

Hammerhead

Your hardened head is a devastating cudgel. It is treated as a natural or melee weapon with which you are proficient and shares the properties of a Warhammer (two handed). A number of times equal to half your proficiency bonus rounded up, in place of a weapon attack on your turn, you may slam your head into the ground causing the ground to quake. Any creatures standing on the surface within 10 feet of you must make a DC (8+Prof Bonus+Str Mod) Strength Saving throw or be knocked prone. You regain all uses of this feature on a short rest.

Octopus

You have four arms and four feet as such your overland movement speed is increased by 5. You may wield weapons with each of your hands. As a bonus action, a number of times equal to your proficiency bonus rounded down you may make a grapple check with an arm that is not carrying anything.

Squid

You’ve got natural ink sacs and you know how to use them! In place of an attack on your turn you may to make an ink spray attack. This spray goes out in a 20 ft cone and any targets struck by it must make a DC 8+ Proficiency + Con Mod, CON Saving Throw or be blinded for one minute. They may repeat this save at the end of each of their turns to try and end the effect early. A creature that has saved from this effect is immune to the ink's effects for the encounter. You may perform this a number of times equal to half your prof bonus rounded up per long rest.

Pistol Shrimp

You’re deadly at ranged attacks even without a weapon in hand. You may use your claw to make a ranged weapon attack with which you are proficient; it has a range of 40/80 and deals 1d8+Dex Mod Cold damage on a hit. This increases to 1d10 at level 5 and 1d12 at level 11. Additionally any thrown items or weapons you use may gain this range if it would normally be shorter.

Whale

Your aquatic trait allows you to be larger than normal, you may choose Huge as your size in addition to the normal Fishmen options. Double your base Ⓑulk capacity if Huge is selected. Your sturdy skin allows you to shrug off more than the average Fishman you gain +1 to your AC. As an attack action on your turn you may expel water from your blowhole in a 30 ft line. Any creatures caught in the blast must make a DC 8 + Proficiency + Con Mod, Strength Saving throw or be pushed to the end of the 30 ft line. Once you use this attack you must submerge yourself in water for one round before you can use it again.

Axolotl

Regenerative Aura: Your natural regenerative abilities can rapidly heal your wounds. As a bonus action, you can activate your regenerative aura to gain temporary hit points equal to your proficiency bonus + your Constitution modifier. This effect lasts until the end of your next turn, and you can use it a number of times equal to your Charisma modifier (minimum of once). You regain all expended uses when you finish a long rest.

Sea Turtle

Shell Defense: You have a natural armor that grants you a +1 bonus to your Armor Class. Additionally, as a reaction, you can retreat into your shell, gaining a bonus of half your proficiency rounded down to your Armor Class until the start of your next turn. While in your shell, your speed is 0, you can't take action, and you have disadvantage on Dexterity saving throws until you enraged out of your shell as a action.

Ancient Wisdom: You have proficiency in the History skill. Your long-lived nature and connection to the past give you insight into events and cultures

Jellyfish

Bioluminescence: As a bonus action, you can cause your body to emit a soft glow, shedding bright light in a 10-foot radius and dim light for an additional 10 feet. This light can be any color you choose. You can extinguish the light as a bonus action.

Stinging Tentacles: You have a number of tentacles that can deliver a painful sting. As a reaction when a creature within 5 feet of you hits you with a melee attack, you can deal 1d4 poison damage to the attacker.

Piranha

Pack Tactics: You have advantage on attack rolls against a creature if at least one of your allies is within 5 feet of the creature and the ally isn't incapacitated.

Bite: Your sharp teeth are a natural weapon, which you can use to make unarmed strikes. If you hit with them, you deal piercing damage equal to 1d6 + your Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.

Frenzy: When you reduce a creature to 0 hit points with a melee attack on your turn, you can take a bonus action to move up to half your speed and make a bite attack.

Eel

Electric Shock: As a bonus action, you can unleash an electric shock from your body. The next creature you touch or that hits you with a melee attack within the next minute takes 1d6 lightning damage.

Slippery: You have advantage on ability checks and saving throws made to escape grapples.

Stingray

Sting: As a bonus action, you can use your stinger to make a melee weapon attack against a creature within 5 feet of you. On a hit, the target takes 1d6 piercing damage plus 1d2 poison damage.

Camouflage: You have advantage on Dexterity (Stealth) checks made to hide in underwater environments.

Electrosense: You can sense the presence of creatures within 30 feet of you that are in contact with the same body of water. This sense does not allow you to pinpoint the exact location of the creatures, but you can detect their presence and general direction.

Sea Horse

Tail Grasp: Your prehensile tail allows you to grasp objects or surfaces. You can use your tail to hold onto an object, anchor yourself in place, or perform simple tasks. While your tail is holding something, you can't use it for swimming, reducing your swimming speed by 10 feet.

Swift Currents: You have mastered the art of moving quickly both on land and in water. When you use the Dash action, you can move an additional 10 feet on land and an additional 15 feet in water. This bonus is in addition to the extra movement you get from the Dash action.