A 4WD flipper-type combat robot. The flipper is powered by magnetic repulsion: internal capacitors release a burst of current into an electromagnet, which repels the flipping mechanism with great force. The capacitors are then recharged to fire again. (It's unlikely to be practical IRL, but it could work in theory!)
Lil' Yeetums has two configurations: a fork-type flipper and a plow-type flipper (shown below.)