Kermit the Frog is notable for appearing in both Sesame Street (often via the Sesame Street News Flash skits) and the Muppets franchise, but I can't recall it ever happening with any other character. According to the Wikipedia article on the 2011 film The Muppets:
A cameo was written for the Sesame Street Muppet Elmo, but was rejected by Disney's attorneys and representatives from Sesame Workshop.
Have any other muppets actually appeared on both media? Or is Kermit the only one?
I'm just interested in officially produced, live-action media, and not things like interviews or documentaries.