Stanley Ipkiss (aka The Mask) is one of the main protagonists from The Mask Comic in 1991 and the main protagonist in 1994 film and the Animated Series.
Stanley's job in the comic was never revealed, but in the film and animated series, he's a bank teller.
In the film, Stanley is played by the Canadian actor Jim Carrey. In the animated series, he's voiced by Rob Paulsen.
In the comic series, he is more of minor character and has a much different temperament.