Rubber Yucchy in Episode 2817
Oscar's grouch doll in Episode 0217
Rubber Yucchy is Oscar the Grouch's favorite bathtime companion on Sesame Street.
The toy is an orange creature made of rubber with spiky protrusions, thick-framed glasses, and sneakers. When it's squeezed, it makes a noise; but unlike other bath toys, it's aggressively grouch-like, making a sound like a cross between a burp and a hiccup.
Oscar recalls a time just after he had acquired Rubber Yucchy when he lost the item in Episode 2817. After running some errands to the Fix-It Shop and Hooper's Store, he returns to his trash can to find that it has fallen out of his pocket. After he retraces his steps, Telly Monster approaches him with Rubber Yucchy, having found it laying on the ground. Luis cites it as one of the few times he's ever seen Oscar sad. The prop resurfaced in Episode 3811, where Ernie gifts it to Oscar's niece Irvine.
Oscar previously had a similar toy that matched his grouch sensibilities, which was originally meant to be a gift to replace Ernie's Rubber Duckie in a season 2 sketch. This toy was larger and bird-like in shape, with thick eyebrows and a disfigured beak. Like Rubber Yucchy, it also made a noise that sounded awful to non-grouches.
After Ernie found his own Rubber Duckie, Oscar kept the doll and used it in Episode 0216 to inadvertently help Miguel demonstrate "t" for "toy," and in Episode 0217 as an attempt to distract a little girl named Polly who couldn't find her mother.