<P> Crystal ( born May 6 , 1994 ) is a female capuchin monkey and animal actress , acquired and trained by Birds & Animals Unlimited , Hollywood 's largest supplier of animals . Her acting career began as a baby monkey in the 1997 film George of the Jungle . More recently , she portrayed the irritating monkey Dexter in the Night at the Museum franchise , and a drug - dealing monkey in The Hangover Part II . In 2012 , she played Dr. Rizzo on the sitcom Animal Practice . </P>
<P> Crystal ( born May 6 , 1994 ) is a female capuchin monkey and animal actress , acquired and trained by Birds & Animals Unlimited , Hollywood 's largest supplier of animals . Her acting career began as a baby monkey in the 1997 film George of the Jungle . More recently , she portrayed the irritating monkey Dexter in the Night at the Museum franchise , and a drug - dealing monkey in The Hangover Part II . In 2012 , she played Dr. Rizzo on the sitcom Animal Practice . </P>
name of the monkey in night at the museum
name of the monkey in night at the museum
Dexter
Dexter