"Big Bully" begins as an evocative, amusing look back at the "Wonder Years" of boyhood, and it's probably no coincidence that director Steve Miner cut his teeth on the pilot of that popular television series.

But it isn't long before "Big Bully" deteriorates into a bad "Saturday Night Live" skit (now, if that isn't redundant), stretched to feature length.

Rick Moranis stars as David Leary, and he narrates the first portion of the film, which is set in a small Minnesota town. There, young David is terrorized by the school bully, Roscoe Bigger, whose nickname is "Fang."

Roscoe bullies David for years, until David's family plans a move to Oakland, Calif. Instead of being upset, as his parents expect, David is ecstatic about the impending move — and before he leaves, he takes the opportunity to tell the school principal (Don Knotts) about something Roscoe has done.

This first quarter or so of "Big Bully" offers an interesting setup, but as the action shifts to the present day, it rapidly runs downhill.

Now the adult David (Moranis) is a big-time author, and he is asked by his old middle school in Minnesota to return and teach a creative-writing class for one semester. "You're the town hero," the letter tells him.

David is a single father with a troubled son, so he takes the position, in the hope that the small-town environment where he grew up might do his son some good.

Upon his arrival in Minnesota, David immediately charms his young class with a lively, humorous approach to creative writing, and he also rekindles a relationship with his childhood crush (Julianne Phillips), now the sex-education teacher.

But his son builds a reputation as the school bully, and his main target is the son of the mild-mannered shop teacher, one Roscoe Biggers (Tom Arnold).

Mild-mannered? That's right. It seems that David's tattling all those years ago sent Roscoe to reform school, and he is now a broken man. With David's return, however, Roscoe becomes aggressive again, terrorizing David with all kinds of practical jokes, ranging from flattening his car's tires to shooting at him with a nail gun.

While you or I might consider bringing the police into this kind of confrontational, threatening behavior, David just runs — thus re-creating their old school-days' bully-victim relationship.

As a result, the film sinks to a silly, childish level as the pranks escalate to ridiculous heights.