What is the oldest Muppet being used in the background

[mupcollector1]

I was just curious since there has been a long history within the huge cast of background Monsters, Frackles, and Koosebanians. Looking back at Muppets Tonight, sometimes they used Muppets that dated back as old as The Muppet Show days. So I was just curious which Muppet is the oldest one still being used in backgrounds as well as the longest used characters in the backgrounds, for example Blue Frackle (sometimes known as Boppity I think) was created in 1970 for The Great Santa Claus switched but rebuilt several times right until The Muppet Christmas Carol and Mopatop Shop. I guess what I mean is not characters that were redesigned and built from scratched or evolved characters like Gonzo, I mean the actual puppets that were used decades ago still being used. Knowing that puppets do wear out, noticing some of the Muppet Show characters being used on Muppets Tonight, they seemed to be in pretty good shape and not like they were rebuilt at all, perhaps repaired. Then again, characters that aren't main spotlight are probably not used as much so that probably explains it a little bit, right?