The Clone Trooper is a small based Trooper of the Separatist faction. At a cost of 10 points, he comes with a small missile launching attack and a speed of 4 tix. His special power is Shootback for one of your Separatist figures.
According to the CD, the Clone Trooper is a 'secret tool of the Separatists', and as such, fights for them against his former comrades. Realistically, this is probably more due to the lack of an Imperial faction in Attactix upon release.