The Robo-Kitty

Flying, first strike, vigilance
Whenever The Robo-Kitty attacks, gain control
of target artifact an opponent controls. Untap it.
Whenever you cast an artifact spell, create a
tapped powerstone token. Then if you control
three or more other artifacts, put a +1/+1
counter on The Robo-Kitty.
Sacrifice an artifact: The Robo-Kitty deals
damage equal to its power to any target.