A Green Monster appeared on Mopatop's Shop in the episode "You Are What You Are".

He was unhappy about being green, when he loved so many pink things. Lucky for him that a Pink Monster was having a similar problem, so they ended up switching colors. However being a new color did not solve all the problems so they decided to switch back. Puppyduck then gave the Pink Monster and the Green Monster, green and pink spots so they could get the best of each color.

The Green Monster was originally used as Blustering Bellowpane Monster on Fraggle Rock.