A loud, obnoxious parent at a kids' little league game who gets into verbal and physical altercations with the opposing team's parents (often due to drunkenness). They have delusions of grandeur that their kid is the hero of his or her team, and that all other little league teams pale in comparison to theirs.
Bat Dad: "Oh yeaaaah! OH YEAAAAHHHH!!! South Park is goin' doooown!Feel it comin'! You ain't got a chance, South Park! Here we go, Denver, here we go! Huh, huh! There ain't no way some little mountain kids can beat Denver, not with MY son on second base!"