characters not seen on Noggin

[minor muppetz]

What characters were never seen in any episodes shown on Noggin?

I never had Noggin, but from what I have read, it seems like the following characters were not shown:
Bruno
Deena and Pearl
Dr. Rainbrain
Aristotle
Rosevelt Franklins mother
Proffessor Hastings

are there any other characters who were not included? Am I wrong about any of the characters I listed?

 

[MuppetDude]

Aristotle's never seen, but is mentioned in #1709. RF's mother has been seen during the "Clap, Clap, Clap" segment in shows #536, 871, and 1364.

 

[minor muppetz]

Aristotle's never seen, but is mentioned in #1709. RF's mother has been seen during the "Clap, Clap, Clap" segment in shows #536, 871, and 1364.

I have read somewhere on this forum that Aristotle was mentioend by name in one of the episodes (maybe Noggin should have shown an episode or two that Aristotle appeared in so that casual fans wouldn't be confused by who Aristotle was).

I have read somewhere that none of the Rosevelt Franklin skits with him and his mother were shown. I guess I misread and didn't think about skits where his mom appeared in the background.