Lamont the Sloth is the name of two different characters in the Muppet media.

Animal Show

Lamont the Sloth first appeared on the "Giraffe & Sloth" episode of The Animal Show where he was performed by Bill Barretta. He tells Stinky the Skunk and Jake the Polar Bear on how sloths make use of trees.

Mopatop's Shop

In Mopatop's Shop, Lamont the Sloth is a deliveryman who occasionally delivers things to Mopatop and Puppyduck