Apparently this happened a year ago, but I’m just finding out now. Apparently after being blackballed from the Magician’s Alliance, Gob Bluth was forced to do a circuit of childrens television shows that included mere tricks (not illusions) for little kids and puppets.
He stopped by Sesame Street, and yes, he’s in at least partial Gob mode, though there’s a distinct lack of The Final Countdown and dancing with a knife in his teeth. I managed to scrape up a video of his appearance which you can watch below, but know that it’s pretty shitty quality.
UPDATE: They do play The Final Countdown! I didn’t even notice.