Improv

I was talking with my player at work about the D&D trip he missed to the mountains.  Well, actually I was telling him about this bold as hell raccoon that got so close to us by the campfire I thought it might run up and snatch a hot dog off the grill.  It showed no fear at all.  At one point it even did a flanking maneuver before eventually disappearing under our porch.  It came back again the next night, even with four players and a dog nearby..

My Player: Did you put it into the game?
Me: Of course . . .

 Haha, I loved that he knew I would do something like that.  I've used player initials on tombs, made a whole adventure based around the job many of us share, and probably other things that were amusing and now forgotten.  The raccoon went on the wandering monster list, showed up while the party was in the Villa of the Terratomancer, but, unfortunately for it, Z was in the form of a wolf and sent it packing.  The real raccoon still lurks. . .

Update: Actually is improv the write term here?  I'm talking more about weaving things about the audience and things the audience knows into the shared world.  Seems like there would be a term for that.  Probably Greek.  Seems like I should know it.