serve little or no purpose. Nixon's head is sometimes accompanied by Spiro Agnew's headless body. Billy West has commented that he is not impersonating Richard Nixon for the role; he is impersonating Anthony Hopkins in Nixon (with "a little bit of werewolf", his Nixon has a tendency to inject a sound similar to "aroo" into his sentences), and that he, instead of trying to cultivate a good impersonation, cultivates the flaws in his impersonation. Matt Groening also frequently expresses his pleasure that he can continue to poke fun at Nixon 30 or 40 years after he was in office. Nixon's head was included in TV Squad's list of the five best television appearances by presidents in animated or puppet form. The character was considered to be particularly interesting because he could be "pure evil" but also command respect and also because "Nixon's head trapped in glass is just really funny." Roberto Roberto (voiced by David Herman) is a criminally insane, psychotic robot who often carries a knife with which he is prone to stabbing. He is often depicted as a patient receiving treatment for criminal insanity. In his first appearance in "Insane in the Mainframe", he is committed to an insane asylum after he targets the same bank for robbery three times in a row, and is seen killing other robots when escaping that hospital. In Bender's Game he states that his creators were trying to make an insane robot, but "failed". This violent nature is enhanced by a body that David X. Cohen and Matt Groening say is based on the shape of a tombstone. Roberto appears in Bender's Game as a patient in the same asylum. He later appears in the Middle-earth spoof scenes of that film as a role equivalent to that of Denethor. He briefly becomes sane after he is hit on the head during a battle, but reverts to insanity after he is immediately hit a second time. He appears in "Proposition Infinity" in the same asylum, this time with a sock instead of his usual knife. He says to Bender, "You ever kill a man with a sock? It ain't so hard." In the season 7 episode "The Six Million Dollar Mon", Roberto is arrested when he tries to rob Hermes Conrad and his wife LaBarbara of their skin. He is executed for this crime, but Bender later digs him up and steals his