Mumbles is one of Big Boy Caprice's minions, a con-artist, and one of the minor antagonists from Disney/Touchstone's 1990 film Dick Tracy.
Role in the film
He starts out as a villain, but later switches sides. He is named for his incoherent speech.
Mumbles getting reformed by telling a departing Dick Tracy that 88 Keys upset him, and his boss Big Boy paid him to get him out of his way