Mr. Pipe is Mrs. Pipe's husband, Eugene and Shawn's father and a reoccurring character in the series.
Like his wife, he is a man who is only seen from the neck down. However, part of his face was seen in "Big Baby Scam" revealing black hair, and rough facial hair. He wears a red robe around his body and has a pipe sticking out his mouth, hence his name. In several of his appearances, he wears rubber nipples on his knees.
Mr. Pipe makes his first appearance in "The Boy Who Cried Rat." After Stimpy woos Mrs. Pipe into accepting his mouse catching offer, Mr. Pipe wants to decline, only to notice a mouse (really Ren) 'beating up on the cheese' and sends Stimpy to apprehend him, giving him five dollars as a reward. After a chase sequence in which Ren and Stimpy pretend to fight each other while simultaneously stealing their food, Stimpy attempts to put Ren outside. However, Mr. Pipe suggests that he eat the mouse and Stimpy attempts to act as though he is eating Ren, only to spit him up, as Ren cannot put up with being in Stimpy's mouth. Ren admits the charade and tells Stimpy to give back the money, only to have him admit that out of hunger, he ate the money. As a result, he and his wife put Ren and Stimpy to work doing chores.
They make their next appearance in "Rubber Nipple Salesman" in which it is revealed that he enjoys chewing them. Ren and Stimpy show many of the uses for the rubber nipples and eventually convince him and his wife to buy several.
He makes his next appearance in "Big Baby Scam" in which it is revealed that he has two sons, Eugene and Sean. In the episode, Ren bribes his sons to leave so that he and Stimpy can take their place and receive free room and shelter. In the episode, he is shown to have eccentric habits, such as forcing his sons to learn how to walk (and almost walk on hot coals), throwing 'Sean' (Stimpy) against the ceiling in a game of catch, and having family bathtime. According to this episode, his father is Old Man Hunger.
He appears as a mailman in "Stimpy's Fan Club." In the morning, he comes to deliver the mail and Ren impersonates Stimpy by wearing a large suit in his likeness. He tries to get Mr. Pipe to stop delivering the mail to the house, only to be told that the only letter he has is for Ren, which causes him to rudely steal the letter and run inside.
In "A Yard Too Far" he purchases a baboon to guard the hog jowls left to cool on the window seal. In one of their many unsuccessful attempts to steal the food, Ren and Stimpy dress up in a large suit labeled 'wife.' However, Mr. Pipe mistakes them for Mrs. Pipe and has the baboon maim them to help the baboon.
He is a kind, manly man. Mr. Pipe loves his wife and listens to everything she says. He also wants his sons to grow up tough just like him so he makes them complete very difficult tasks. He's also not afraid to be seen nude in public. In many of his appearances, he is shown to have eccentric attitudes and tastes. In "Big Baby Scam" it is shown that he wanted his sons to learn how to walk, then walk on hot coals, and it is later shown that he and his family all have a daily bath together. In "A Yard Too Far" he is shown to have purchased a baboon in order to guard the house.
- It is possible that he may be related to Old Man Hunger and, by extension, Mrs. Buttloaves, as he is shown living with the Pipes in "Big Baby Scam" and both characters don't mind being naked in public.