Potsie tells Richie and Ralph about Laurie Glass whom he helped in Biology. She comes over to their table and thanks Potsie for helping her draw the digestive system. She asks him to draw the reproductive system for her. Laurie's boyfriend (Bernard) confronts Potsie and calls Fonzie "Big Mouth" after he comes to Potsie's aid. Fonzie takes Bernard outside to beat him up. Richie talks to Fonzie, and he thinks Fonzie's been getting in a lot of fights lately. Fonzie comes over to the Cunningham house and tells Howard and Richie about his fighting situation. Howard tells Fonzie to snap out of it. Marion says that Howard once went to a psychologist to help him stop eating. Fonzie tells them to make an appointment for him. Fonzie goes in to see Dr. Brendel to talk about the street fights and violence in his life. Fonzie tells him that he doesn't have a girlfriend but that he goes out with 150 girls. Dr. Brendel doesn't believe him and calls in Richie to talk to privately. Richie confirms what Fonzie has told the doctor. Dr. Brendel sees Fonzie with the secretary, Miss Franklin. The doctor says they need to find an outlet for Fonzie's aggression by having him build birdhouses (he can hammer nails when he builds birdhouses). Joanie comes into Arnold's wearing Fonzie's leather jacket. Fonzie comes in wearing a T-shirt and carrying a birdhouse. Butch, Bernie's brother, comes to settle the score. Butch damages the birdhouse, and Fonzie barely keeps his cool. After a discussion at the Cunningham house, Fonzie returns to Arnold's and fixes the birdhouse he made for Al with a little rotating "A" on it. Fonzie retains his cool until Butch and Bernie show up, and Butch touches him. Richie gives Fonzie the okay to "get him," but Fonzie lets them off the hook and scares them off.
Songs in this episode:
"Bird Dog" by The Everly Brothers (1958)
"Tequila" by The Champs (1958)
"Personality" (instrumental) by Lloyd Price (1959)
"I'm Walking'" by Fats Domino (1957)