Insane Player

Insane Players were regular people, volunteers of the experiment, but they stayed in the experiment for so much time that they just went insane, usually stopping in one single place. The names, clothes and items in hand are all randomized. They drop skin and organs at death.

(They aren't actually insane, mostly)

Zombie

The Zombie is a highly hostile creature rising back from the dead and spreading its infection. It is slow and has a low resistance, but it can quickly create a whole army if someone isn't cautious enough. It drops organic gump at death.

Bugs

Bugs are gigantic green insects which like to have protection, usually wearing things on their torso and head, as those are strangely their weakest parts. They are weak in general, but 'clothes' help them. They drop string at death. If they're wearing something, they'll drop that.

Robots

The Robots come in different variants, being friendly, neutral, aggressive, or broken. Broken Robots can be repaired with robot parts, obtained in containers or by killing other Robots. They then turn into Robot Servants, who protect and obey the maker. They drop robot parts at death. The Robot Servant, instead of dying, when killed it becomes a Broken Robot.

SPOILER ALERT - IF YOU WANT TO FIGURE THIS OUT YOURSELF DON'T HIGHLIGHT THIS TEXT

Ectoplasm can be used on a Broken Robot to create a Possessed Robot.

Possessed Robot

It's a flying robot that's pretty strong. It is obtained by (look at the spoiler up here). It drops ghost metal at death.

Manneking

NOT TO BE CONFUSED WITH MANNEQUIN

The Manneking resembles a normal mannequin, like any other, but trembling, with white eyes. When someone looks at it, it immediately disappears and damages the looker by 2 health. It cannot be hit or killed.

Magno and Magner

Both the Magno and Magner are human-sized magnets with legs, with the Magner being bigger. The Magno's primary color is red, the Magner's primary color is blue. The Magno is a 'pull' magnet that follows people holding metal items, while the Magner is a 'push' magnet that kills them. The Magner has 12 health, the Magno has 8.

Ghost

The Ghost is a passive invisible entity, appearing as a floating eye. It has a 1 in 50 (variable) chance of spawning when waking up. It is friendly, and keeps being friendly, until a nearby person steps. At that point, the Ghost enters an aggressive state. However, triggering it can be avoided, as it disappears 20 seconds after spawning. It drops ectoplasm at death, but not when disappearing.

Meatball

The Meatball is an aggressive entity appearing as a floating meatball, it causes an explosion when hurt or touched in general. For this reason, it is immune to explosions. It is advised to keep distance while fighting the Meatball. It drops meat at death.

Tesla Slime

The Tesla Slime is a slimy 'aggressive' entity that inflicts any person stepping in a 3 block radius with the Conductive effect for 30 seconds. It is advised to crouch when going near it or, if trying to fight it, keep distance.

mag.net

mag.net is a boss that always spawns in the server room at room 50. It occasionally spawns minions: Magnos, Magners and Serverbugs. It has 100 health and drops a mag.net card which can be used to escape the room.