Otto

Otto Mann is the school bus driver for Springfield Elementary. He is a premium character, and a part of the School Workers collection.

Simpsons Wiki Description
Otto Mann, known as Otto the Bus Driver prior to Season 8 (and so stylized after Bart calling him "the Otto man" on several occasions), is a former school underachiever and later college dropout who now works as the bus driver for Springfield Elementary. Otto was initially conceived by Shearer himself as a caricature of metal music aficionados who mostly play guitar and do drugs while occupying a low-level labor job. He then became a character well-known for his party tendencies and calling others hippie-junkie slang ("dude", "lady" or "pops"). He is friends with Bart on some occasions, minus their age difference, and dreams of starting his own rock band to become a celebrity, all while getting the school bus into trouble one time after another.


 * Read the full article here at Simpsons Wiki.