Gross is the main antagonist of the children's TV special Lamb Chop in the Land of No Manners.
Gross is only shown in pen-drawn outline, and despising good manners, he bans them. Anytime rude visitors enter, he keeps them in.
When Hush Puppy, entering the Land of No Manners to give Lamb Chop a peanut butter sandwich, teaches one of the monsters, Belch, to say "please", and it happens to everyone, there is an exception: Gross. He hides because good manners are contagious.
One day, when Charlie Horse finds the doorway to the Land of No Manners, Gross demands Charlie come in, but politely, Charlie declines, to Gross's dismay, so he simply slams the door.