This is an officially licensed Family Guy product.
The evil monkey in Chris's closet is a cult favorite character. Chris mentions the evil monkey in the following Family Guy episodes:
Dammit Janet: "If you get a job, who's gonna feed me and protect me from the evil monkey in my closet?"
Fore Father: "I want to go, Dad. It'll get me away from the evil monkey that lives in my closet."
Emission Impossible: "I don't want to go to my room. There's an evil monkey in my closet!"
Ready, Willing, and Disabled: "We can't keep it in my room because there's an evil monkey that lives in my closet. You know, the sad part is, he wasn't always evil. [Evil Monkey sees wife in bed with another monkey, crazy monkey screaming ensues]"
Brian the Bachelor: "[Evil Monkey points at Chris] I AM IN NO MOOD!"