Gus

Gus is one of the main antagonists, and was a former night guard with Cecil Fredricks and Reginald. He is portrayed by Mickey Rooney.

Night at the Museum
Gus is a main character in the first film. He is first seen with Cecil and Reginald when Larry gets the job as a night guard. He is later seen when Larry tells them that they didn't say that the exhibits came the life at night (this was because they thought Larry wouldn't believe them). He is shown at the end of the film to be very strong for an old man, as he punched Larry very hard in the face. He is also grumpy and rude.

Night at the Museum: Battle of the Smithsonian
Gus appeared in an alternate ending of Night at the Museum 2.

Night At The Museum: Secret of the Tomb
Gus has a minor role in the third film, as he, Cecil, and Reginald are now in a retirement home.