Hello, so lets get this started.

SCP-005: You know the model and exactly what it does. Rarity: 10% chance in its own room (box of horrors 005 room)
SCP-682: You have the arm texture, and the sounds, but actually add him. Rarity: 30% anywhere.
SCP-079 Functionality edits: Why can't he LITERALLY control the facility? Control containment doors, do more gas, (if 682 added) send 682 after you, and basically f**k with anything computerized, like containment doors and gas.
SCP-009: Sometimes appearing in "Cup of water" without telling you, killing you after 3 seconds of drinking. Also has a chance to be in the water for the tree. Rarity: 20% chance on anything water-based, including you, with the same effect as in drinking red ice cup of water.
SCP-131: Will roll around you, as if a pet, if you see it. Will squeak near hostile enemys, and if SCP-173 is in the room, it will follow you slowly, but stare at it to stop killing you. Rarity: 30% chance for spawn anywhere.

Well the SCP-682 will be really hard to put in the game. Simply because of the masive destruction that he will cost.

True. Which is probably why Regalis put adding 682 in off for so long.

Personally, I like the idea of having 005 in the game, and I thought my idea of spawning it in 409's containment chamber, and having 079 shut the door on the player if remote door controls aren't off would've balanced it out. But I guess some things don't really fit in CB.

Also, there are metric crap tons that could be added in to CB. I've been kind of posting my ideas all over the place, but I don't think a new thread is necessary, if I'm to say anything about it (especially considering how there's a suggestions thread).