Baron Ünderbheit was one of Dr. Rusty Venture's old college friends on The Venture Bros. However, after a freak lab experiment in which Rusty was his lab partner, Baron Underbheit's mouth was disfigured and he was forced to wear a metal jaw. Since then he has seeked revenge on Venture.
The Baron is a member of the Guild of Calamitous Intent and lives in Ünderland, where he rules with an iron fist. However, during the second season, the Baron was ousted from his land and was last seen begging for a place to stay from the Monarch.