Dr. Zemu is the man who created the cybernetic limbs of Axel's disfigured body parts. After Axel broke free of his wheels in Twisted Metal 2, Dr. Zemu created robotic hands and feet to take the place where Axel's limbs once were. Zemu only appears in Twisted Metal: Head-On, pressuring Axel and keeping him from stating his wish for winning the competition. He pulls out a remote and controls the cybernetic limbs to enter back into the wheels and electrocute him. It caused Axel to end the word "peace" with a scream, confusing Calypso into thinking that he wanted pizza. Adding a scream at the word "peace" sounds like the word "pizza". Zemu succeeds at preventing Axel from wishing for the Twisted Metal contest to be stopped.