Otto Mann (voiced by [Harry Shearer]?) is Bart and Lisa's school bus driver. He is notable for his occasionally manic driving style and his propensity for sounding and acting like a perpetual 70's teenager.
(Has Otto's backstory ever been filled in?)
His father is an Admiral, and the two don't get along. There have been suggestions that this is a reference to Jim Morrison of The Doors, whose father was also an Admiral.