How would you add a human NPC in Portal 2? I'm not talking about the player's model, but a real ragdoll, specifically the G-man if possible. It doesn't matter if it's not fully functional, I just need him to stand in my mod. (npc_gman is not showing up in Hammer with the authoring tools.)

You Mean Like this?

http://www.youtube.com/watch?v=5h9JlC_E1Fc
If so, as the video says, an NPC_generic_Actor, Im not quite sure how to use it, I think there is a tutorial in the description, I hope I helped!

Edit: I think you have to port the models over, or for the Npc_gman, you can also port the models/materials over to the portal 2 binwhatever folder it is, sorry, I don't have portal 2 on this computer so I cant check where The folder is. Hope I helped!

I actually tried putting in a walking npc and it didn't work whatsoever. Even downloading this map here: post44195.html and recompiling it failed. perhaps this feature was cut out to make portal2 a smaller engine.

Try compiling inside alien swarm sdk and see if it makes any difference.

Also refer to: post49354.html . It was explained a tiny bit.

EDIT: Just realised you don't care if he moves. Try importing the model and animations over and you can create a prop_dynamic and set his animation to a standing idle one. That way he is standing there etc.