A series of minor characters, more for people who want to play multiple roles:

Phil the Turtle - An incredibly stoned jerkass who loves tormenting Master Roshi.

Ox King - Proud, uptight, rarely admits when he's at fault.

Chi-Chi - Naive and absent minded, similar to Goku, although more easily upset and with less violent tendencies, although quick to violence when frightened.

Monster Carrot - Casually mad. Speaks with a very reserved demeanour, but discusses absurd concepts and ideas.

Shu and Mai - Basically Richie and Eddie from Bottom

Also, random bystanders can be voiced by ensemble performers.