The Simpsons: 10 Springfield Characters You Totally Forgot Existed
3. Frank Grimes Jr.
There have been many classic characters introduced in The Simpsons over the years, with some needing no more than a single episode to make their mark and create their Springfield legacy. Frank Grimes is arguably the most popular and memorable of these one off characters, but the same can't be said for his son.
Six years after his father died in the Springfield Nuclear Power Plant, Frank Grimes Jr. returned to exact his revenge on the man he believed to be responsible. He tried to kill Homer by locking him in a steam room, he shot at him in Moe's, and he cut the brakes on his Mardi Gras parade float.
Of course, it made sense to bring in someone who knew more about murder than anyone else in Springfield, even though he never actually killed anyone. It may be that Sideshow Bob's role in the episode overshadowed Grimey's son, which in turn led to him being forgotten. Or it could simply be that he wasn't nearly as compelling or sympathetic as his dad.
The son that was apparently mothered by a hooker Frank Sr. liked saw his plan foiled by Sideshow Bob, and never appeared in the show again.