Mister O

Mr. "O" shows his startled son how to scare up business.

Mr. "O" is a human in the Generation 1 continuity family.

Mr. "O" is the father of Buster Witwicky's best friend "O". He runs a diner in Portland, Oregon, called Mister "O"'s.

Fiction

Marvel Comics continuity

When the Transformers made their presence known on Earth, Mr. "O" put on an Optimus Prime costume to attract reporters and customers to his business. His son was not impressed.

We were never told what the "O" stands for. The Last Stand