When the boys are playing baseball, Randy Marsh gets drunk and starts trash-talking and fighting other parents. He does this confidently, until he meets Tom Nelson, who refers to himself as "Bat Dad". Bat Dad intimidates Randy, making him realize he may not win the next brawl. He decides not to attend the next game.
During the game, when the boys are about to win, Randy turns up to confront Bat Dad. Randy is certain to lose the fight, when the announcer intervenes. He declares the next person to fight will have their team disqualified. The boys, wanting to lose, persuade Randy to finish the altercation. Randy repeatedly hits Bat Dad, causing his team to be disqualified.
It is unknown who his child/children were at the little league games he was attending.
Bat Dad wears a purple Batman mask and cape, as well as a black loincloth and a black wristwatch. He is shown to be overweight.
Tom Nelson as "Bat Dad" is loud and obnoxious, ruining the game with his trash talk. He is also egotistical, believing when the umpire tries to break up the fight that he had already won. His ridiculous antics were likely an attention-seeking ploy.
- Despite being named as Tom Nelson on the television, his wife/partner addresses him as "Chris", which is likely an error on the show's behalf.
- ""South Park" The Losing Edge (TV Episode 2005)". IMDb.com.