Ah you are talking about a character who is following (chasing) around your currently active character? I actually wrote a script for
Joe, that allowed characters following around his active character perform random animations when the active character becomes idle. I suppose you could take the same script to control both the random actions & stop them & have them resume following the active character when it starts moving again. I believe the script took care of both following & idle, then again I have bad memory & I wrote it a while ago.