As far as can be determined, Bon appears to be a baby inside a robotic body, and is the youngest of the three siblings that make up the Bonne family of air pirates. His exact age is undeterminable, somewhere between "too young to say anything but babu" and "old enough to do battle within a complex robot." Sadly, Bon's limited appearances prevent him from being a very stand out character, but there's no denying the Bonnes just wouldn't be the Bonnes without him.

The Misadventures of Tron Bonne -

Bon's appearances are both sadly short-lived. He accompanies Teisel on the Nakkai Desert mission at the beginning of the game, and is taken captive along with him. After that, he's seen only briefly helping out at the end of the game.

Mega Man Legends -

When the Bonnes target Kattelox Island, Bon's role in the attack is to wreak havoc on the upper-class section of town and City Hall itself, until the mayor surrenders the keys to the island's sub-gates. Bon has little to add throughout the remainder of the story.

Mega Man Legends 2 -

As the Bonnes compete in the quest for the Four Keys to the Mother Lode, Bon has little to say but gets in on the action plenty. He appears in various forms, from his standard configuration to part of a train locomotive.