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.