Mumbles was the guitar player of the “Mumbles Quartet” a band that booked and performed at high-class parties after which they would rob their hosts. When Mumbles was “ratted” out by their singer, Kiss Andtel, Mumbles and the gang stole $60,000 in cash and kidnapped Andtel, escaping on a boat. Mumbles rigged the vessel to explode and dived overboard with the cash. Dick Tracy arrived in time to save the remaining members of the quartet and Kiss Andtel.
Many years later, the remaining three members of the Quartet were approached by agents of the new Mr. Crime and asked to work for their old boss. They agree and the Quartet gets together to make Vincent Vinyl have a deadly accident. Mumbles is dating Vinyl’s niece Kassie Ette and hopes to get in on the life insurance, however he is stupid and feeds Vinyl’s body to a Muerte vine so there is no corpse. Still he tries to have the life insurance paid out, getting the attention of the police. The remaining members of the Quartet are fed up with Mumbles and approach Panda (a lieutenant for Mr. Crime), hoping to get rid of him. Panda arranges for a meet with the Quartet, but never shows. Instead a bomb is rigged to their vehicle by Abner Kadaver and they are killed in a car bomb as a warning to Mumbles to keep his nose clean.