Otto

 Otto  is a Grouch resident of Grouchytown, the hometown of Oscar the Grouch.

Otto made his very 1st appearance in episode 2538 of Sesame Street, being a member of a tour of Sesame Street Oscar  was giving to some of his old friends from Grouchytown.

Later on in the day, the Grouches observe Gordon ordering a milkshake. Oscar tells him they're 1st-time visitors &  Velma  offers him a chocolate -covered fish head. He turns it down, but offers her a bite of his turkey salad sandwich, which disgusts her at 1st, but she tries it anyway. Otto takes pictures of them w/ the food.

Later that day, as Oscar  & the Grouchytowners reconvene,  Worby  complains that he's sick of being patted on the head, & wishes he was back in Grouchytown. Velma & Otto are homesick too, & the 3 sing "Dear Old Grouchytown". A sympathetic Oscar  agrees to end the tour & take them to the bus stop.

TV/Movies/Specials

 * Sesame Street
 * Episode 2538
 * Episode 2648 (possibly)
 * Episode 2899 (possibly)