In the early 1990's, the Jim Henson Company released this "Swine Trek II: The Bath of Pig" image as a poster:
Of course this wasn't the first time The Muppets had spoofed the series - most notably in The Muppet Show's Pigs In Space segments:
These segments were so popular, they received their own book and lunch box!
Which featured Leonard Nimoy:
and Beaker taking a Star Trek inspired cruise with George Takei:
There have been many other Henson/ Star Trek connections over the years as well.
Muppet Babies had a few episodes were the characters imagined themselves as the crew of both the classic and Next Generation Enterprises:
Sesame Street, Farscape, and even Fraggle Rock had references to the final frontier too:
For a full list of Muppet spoofs and references check out the Muppet Wiki's Star Trek page.
One of the mostly unknown connections is that in the late 50's/early 60's, Sir Lew Grade wanted Roddenberry to develop a series and set up his own production company in England. If that sounds familiar, it's almost exactly what happened to Jim Henson almost a decade and a half later!