Van Zant is a madman character unnamed in the Dragon Ball manga, but named in the anime Dragon Ball Z. First appearing in the Majin Buu Saga, he is a deranged gunman who enjoys killing people (apparently, with the rationale that since it is "the end of the world", he wants to go out with a bang). In the Japanese version and the manga, Smitty refers to him as "young master," implying that Van Zant is from a wealthy family and that Smitty is his butler and/or servant.

(Source: Dragon Ball Wikia)