Utterly Mad

I dunno how much of the Cata stuff is externalized anymore, but take a robot, rename it to something that isn't robotic-sounding, and use that. The logic is in place for them to kill things besides the PC already.

Oooor I could do what I'd ALREADY been doing and take literally any monster that has enough aggression (and relies on attacks that aren't hardcoded to only affect players). The code's already in place that anything spawned as friendly will attack enemies unless they're too passive to bother, regardless of what they're normally hostile to.