Fenwick is a recurring monster on Sesame Street in the early 70s. Sporting a look unique to him, he has orange exposed skin on the lower half of his face, while his head (and sometimes his eyes) is covered with orange fur.
He had a single tooth in his first appearance (performed by Jerry Nelson) during a sketch with Grover and other monsters demonstrating an empty and full room (First: Episode 0148). He had no discernible performer in a segment with Billy trying to figure out the word "IS" (First: Episode 0168). He later appeared on the street in Episode 0210 (performed by Caroll Spinney) with Bob, Herry Monster, and other Anything Muppet monsters for the song "Don't You Know You're Beautiful?"
Fenwick's name originated in a season 3 segment (performed by Jim Henson), where Herry tells Grover a secret (the alphabet) and spreads it to other monsters (First: Episode 0360). He is seen hiding in a paper bag throughout the segment.
The puppet has also appeared in the monster tug-of-war sketch (performed by Spinney), in Grover's rowboat sketch, as a background singer in the original "C is For Cookie," and in a season 4 segment (performed by Jerry Nelson) with Pamela (where Billy scares them off after growing bigger) (First: Episode 0474).