Takei, Beaker, and some penguins.
George Takei (b. 1937) is an actor best known as Hikaru Sulu on Star Trek.
Takei appeared in Muppets Tonight episode 211, regaling Beaker with a steady stream of Star Trek stories.
During the episode, Takei had a chance of becoming a naval captain, but then he met Captain Kangaroo, who was also on board. The Captain was the highest-ranking officer on the cruise ship, so he became "Acting Commodore Kangaroo", much to Takei's chagrin. Said Takei, "Mr. Beaker? Set ego to bruised."
Takei's other credits include playing himself on The Simpsons, Futurama, 3rd Rock from the Sun, Will & Grace and The Big Bang Theory, a recurring role on Heroes as Kaito Nakamura, and guest roles on Murder, She Wrote, The Six Million Dollar Man and The Twilight Zone.