Although in the first season, Nelson seemed to be Bart's antagonist, he becomes Bart's friend in later episodes. In the earliest episodes, Lisa became the target of Nelson's bullying, which prompted Bart to defend her. His actions resulted in frequent beatings by Nelson and his gang, but finally ended when Bart received help from a shell-shocked Vietnam vet, who came up with the idea of standing up to Nelson and his gang by pelting them with water balloons. From that point on, Nelson gained respect for Bart, though he occasionally reverts back to his past behavior towards him, though much less severe.