Pecks Beefcake is the main antagonist of the Heathcliff episode, Heathcliff Pumps Iron.

He first appears while Heathcliff and Sonia are planning a river boat date when he kicks Heathcliff to the side and flirts with Sonia. Admiring his muscles, Sonia walks away with Pecks. Heathcliff then goes to the gym to pump iron and defeat Pecks in a weightlifting contest. The trainer of the gym sides with Pecks and sabotages Heathcliff's efforts. However because of some of Heathcliff's pranks and luck, Pecks would often get injured.

During the contest, the trainers sabotaged Heathcliff further, making Pecks the winner. When Heathcliff finds out about the cheating, he punishes the trainer in typical cartoon fashion and sabotages the boat ride by drilling a hole in the boat. When Sonia asks Pecks for help, he shows off his true cowardly nature and narcissism by saying that he wants to be saved. Heathcliff arrives in another boat and rescues Sonia while Pecks begins drowning after the boat capsizes. Heathcliff "rescues" Pecks and launches him onto the capsized boat. The boat sinks along with Pecks.