Agreed. 64 episodes from the original version, three adaptation sitcoms (2 animated), and the first movie, only to see this fly-by-night addition in the sequel movie. Seems like this should be a bonus answer, or this grouping should be removed from this quiz.
I tried Zach and Zachary, then gave up on that one. This one was really difficult for me. Completely forgot about the youngest Van Pelt and kicked myself for the Gondor one - I immediately thought it must be a Game of Thrones family, didn't even think about LOTR. Duh.
Rerun was introduced to Peanuts sometime in the early '70s and featured occasionally until sometime in the '90s, at which point he became much more prominent. For the last few years of the strip, he was practically the main character.
I must have had a serious mental block. I could not get Hansel and Gretel for the life of me. For fairy tale witch killers I tried to think if Van Helsing had a sibling, he does for future reference (Abraham and Cornelius), then I thought the Brothers Grimm probably killed a witch or two. But I couldn't think of their names either. (Jacob and Wilhelm) Needless to say I didn't get what should have been two of the easier answers.
Are Romulus and Remus really fictional characters? Of course the story of the former's founding of Rome is mythologised to the point of complete fiction, but just because his actions are myth doesn't mean the historical record of his existence as a central figure in Rome's early history isn't as good as (or better than) that of any other figure living at that time. I'm willing to believe that Remus is a figment of the imagination, simply because twins make for a great storytelling device, but I'd say that for all we know (which admittedly isn't an awful lot) Romulus did exist.