Long before Avengers: Endgame mastered the art of the franchise-wide crossover, Jim Henson had attempted a similarly showdown. A Muppet Family Christmas aired in 1987, and was the first program to feature the Muppets alongside the Fraggles, the Sesame Street crew, and even the Muppet Babies (presented here as puppets!). Unfortunately, the later home video releases of A Muppet Family Christmas had to excise certain scenes due to licensing issues between the different character families (even today, the Muppets are owned by Disney, but Apple has the Fraggles and HBO has Sesame Street).
The good news is: someone has finally uploaded a VHS rip of the original video onto YouTube — complete with the original commercials! Some of my earliest memories are from this airing. What a delightfully charming holiday time capsule.