Sorry - not quite ground works for a Terminator game (way too many skulls for my liking) but I've just based one of a set of three children's Terminator prosthetics as a bit of loose scenery:
The original pack (modelled by my own
fair left hand) :

A quick plasti-card base, a bit of paint and wash, glue and flock gives me:

Full details can be seen on
my blog hereAndrew