Joe Doe is a member of the "RSI: Rhyme Scene Investigation" on Sesame Street. He, along with colleague June Moon, tries to help the Fat Blue Anything Muppet (performed by Martin P. Robinson) find the thing he lost that ends in "at."

The puppet for Joe Doe is made out of the modified orange live-hand Anything Muppet with orange rod arms added. He is an Anything Muppet caricature of David Caruso with Caruso's red hair and trademark CSI sunglasses.