Wow... too tough to call who would make a good sixth Fraggle. I can definately see an argument being made for Tosh, Lou, Large Marvin, and Marlon. Personally, I would have loved to see Cantus, but that's just because he's my favorite Fraggle (well, him and Boober) and I've always wished (tis a tiny wish for Fraggle Rock is as close to perfect as any TV show shall ever get) there were a bit more of him in the series. But in all reality, I actually do consider Uncle Traveling Matt to actually be the six Fraggle. Sure, he might not have been in the rock the whole time, but he was in nearly every episode and his spirit was ever-present in the the heart of Gobo.