This is mainly for @tawdry elm. But others can put ideas here too
Malhare-you can find the vanny mask as a priceless scrap (0 credits) however using it allows you to spot scrap through walls (gotta be semi close by though). Moment you put it on he does what he does in ruin dlc. Once he catches. He can either straight up kill you. Or spawn in a random ruin animatronic.
Balloon boy-steals your flashlight and runs off with it
Scraptrap-purely an outside enemy. Randomly will spawn and rush for the ship door. Close it in time or else. After a few seconds of it being closed. He will run far enough to not be seen. Then repeats at random intervals
Puppet-can find his music box as a pretty expensive scrap. Once picked up it will immediately begin winding down. You have to keep it from completely winding down. Dropping it once picked up will still cause it to wind down. Once its all the way down the puppet spawns and chases the player that either has the box. Or the player closest to the box
Molten freddy-will be hiding in a vent. Walk too close and he kills you. You can tell if hes moving around vents by his laugh
Mangle-walks on the roof. If its a high roof then it jumps down and kills you (similar to the snare flea. Just without the slow choking) if its a small roof it can kill you normally
Phantom bb and mangle- bb will show up on the terminal. If you dont leave it fast enough. It jumpscares you and gives you the ringing effect. Mangle does the same but instead of jumpscaring you. It appears and just does what it does in fnaf 3.
Springtrap-slowly wanders the facility. Attracted HEAVILY to noise. If he spots someone he does his jumpscare noise. Then runs straight for you. Only way to avoid him during this is to get away from his line of sight and be completely silent. Then he goes back to wandering.
Phantom foxy-occasionally pops up randomly. Stare at him for too long and he does a jumpscare similar to phantom bb