80s Trivia: Which of these characters was not on Fraggle Rock?

Fraggle Rock was, bar none, my favorite all time 80s TV show.  It was hysterical, adorable and provided grown-up lessons in a language that kids could understand and adults could appreciate.  To those of us who loved the show, its cast of characters is legendary.  So, here is today's question, off of Pocket Trivia: 80s Trivia -  Which of these characters is not from Fraggle Rock?  Is it The Trash Heap, Boober, Gonzo or Sprocket?

The Trash Heap (Marjorie) was the oracle of Fraggle Rock, dispensing wisdom to all who sought it.  She was, as the name would imply, a big ole trash heap.

Boober was the anxious Fraggle, but one of the five main characters.  He loved laundry and worrying (side note - my sophomore year of college, as part of a psych project, my group diagnosed Boober with a Generalized Anxiety Disorder.  The dude worried way to much!

Anyway, Sprock was Doc's loveable dog.  He was one of the few who could actually see the Fraggle's and spent much of his on-camera time trying to convince Doc that the Fraggles existed.

Anyway, the answer is Gonzo.  Gonzo, a Weirdo (not only in personality...that was his species), appeared in numerous Muppet films, TV shows and cartoons.  He loved Miss Piggy and Camilla, his chicken (gotta love the matter of fact way you can say that) and was good friends with Kermit, Fozzie and the rest of the gang.  He did not, however, ever appear on Fraggle Rock.