That's Rich's adversary, inasmuch as he had one. Reggie Van Dough. We know he's a jerk becaues he has freckles and big eyebrows and, most important, is not blond. The wikipedia entry says:
. . . known for playing constant pranks on everyone, most notably Richie and his family, which causes his father to punish him.
The means of punishment are not specified, but you assume it means loss of privileges; Reggie looks like the kind who could bear a whipping with a grim sadistic smile. Here's what the entry says about his mother:
. . . not as quick to punish Reggie for his pranks, but she doesn't tolerate Reggie's unabashed cruelty either. It is never clearly determined if Vanessa is related to Richie's mother or his father.
Because no one cared one way or the other, that's why.