Yorick is a character that I find tantalizingly wonderful. Tantalizing because, well, very little of Yorick has survived the years.
Yorick was one of the first Muppets created by Jim Henson. I think there's a real possibility that he was the second one, actually. He was created and built in 1954, just after Jim graduated from high school. While still a senior, he was approached and hired by the manager of a local TV station (WTOP in Washington, DC) as a puppeteer on a new Saturday morning show called The Junior Morning Show. That was Jim's television debut, and the debut of his first puppet character: Pierre the French Rat.
The next year, Sam and Friends started, and Yorick was right there in the cast. Yorick is generally just a purple skull who is perpetually hungry. He's a papier mache puppet, and has a tube in his mouth so he can swallow things. Though he occasionally lipsynched to records, he generally didn't speak, usually grunting if he verbalized at all, though he did very rarely have lines.
The unfortunate thing is, of the few episodes of Sam and Friends that we still have available, Yorick is only in two of them. He's the star of this one, though, appearing for the only time with a hand and lipsynching to Ken Nordine's jazz piece "Where Hunger Is From." (The person who posted this synced it up with clear audio.)
It's really too bad that we have so little of Yorick, as a poll of Sam and Friends viewers found that Yorick was the show's most popular character. (Sam came in second, with Mushmellon third and Kermit a very close fourth.) Yorick didn't really appear in any Muppet productions, except for a cameo (with Harry the Hipster and Sam) in the 1986 TV special The Muppets: A Celebration of 30 Years.
Except for this other clip. One of Jim's bits that he performed on several different shows (but not, oddly enough, on The Muppet Show, which is where most of those bits eventually ended up) saw Kermit lipsynching to Rosemary Clooney's recording of "I've Grown Accustomed to Your Face." This was actually the first bit Jim ever performed on a network TV show, premiering it on The Steve Allen Show in 1956, and reprising it for Jack Paar, Ed Sullivan and Johnny Carson. The performance that I found on YouTube is from that classic 1971 Dick Cavett Show episode.
Yorick now resides in the Smithsonian with his fellow Sam and Friends cast members. But I wish we had more of his appearances.