Star Wars : Droidekas

The Droideka, or Destroyer Droid heavy infantry unit are seen in the prequel films. These droids can transform, appearing first in a "wheel" state allowing rapid movements and easy storage, then unfold into insect-like attack-robots with a slow three-legged gait. In their walking state, Droidekas have powerful twin blasters on each of their arms, extremely accurate in close range and a personal shield generator.