An unemployed guy got a job at the zoo, pretending to be a gorilla. On his first day on the job, the guy puts on the gorilla suit, goes into the cage and starts really putting on a show, jumping around, beating his chest and roaring. The people all cheer and applaud, but during one particularly acrobatic attempt, he loses his balance and crashes through the safety netting, landing square in the middle of the lion cage.
As he lies there stunned, the lion roars. The guy in the gorilla suit is terrified and starts screaming, “Help, Help!” The lion races over to him, places his paws on his chest and hisses, "Shut up, or we'll both lose our jobs!"
—From Workplace Jokes: Only SOME of Them Will Get You Fired!