It is shown in many episodes that Nelson's father abandoned him and his mother at an early age when he "went to pick up some Pop-Tarts" although, later on in the series, he was said to have gone to pick up a pack of cigarettes. In the fourth-season episode "Brother from the Same Planet", Nelson's father is the children's soccer coach who awards Nelson with a free trip to Pele's Soccer and Acting Camp. Nelson's father also appears briefly in the sixth-season episode "Bart's Girlfriend", depicted capturing Nelson with a leash as the children run through the cornfields in an attempt to avoid attending church. He also appears in the ninth-season episode "Bart Star" to congratulate Nelson after a football game victory and take him to Hooters (with Nelson turning down the invitation because he "doesn't want to bother Mom at work"). Nelson's father returns in the sixteenth-season episode "Sleeping with the Enemy". It turns out that he did not leave Nelson deliberately; he bit into a chocolate bar, not knowing it had peanuts and had an allergic reaction, covering 90% of his body with large tumors. Looking like Joseph Merrick, he ran out of the store and encountered a circus that made him a part of its freak show. At performances, circus attendees threw peanuts at him, which perpetuated his reaction, preventing him from returning to normal. When the circus came through Springfield, Bart recognized him and brought him home to rid himself of Nelson (who had been taken into the Simpson home by Marge).