My Pet Monster (1987)

My Pet Monster is a 1987 animated series based on the plush toy character of the same name, a blue, furry, horned creature with orange chains. The 13-episode cartoon, unrelated to the 1986 direct-to-video special, is about the creature, called Monster, who lives with a boy name Max who keeps his existence a secret aside from his sister and best friend.

E3: Boogie Board Blues
As the gang prepare to go to the beach for the Junior Boogie Board Competition, Monster tries on a vest, which inflates to massive proportions and sticks out of their treehouse. Unable to find and reach the plug needed to deflate it, Max is forced to pop it with a pin.