One of the most distinctive characters on Sesame Street is Oscar the Grouch.
Most people think the Grouch refers to his attitude, but in reality, this is his species, he is a Grouch from Grouchland.
As for inspiration, the character’s origins are channelling a New York cab driver - his first line in episode 1 (1969) is ‘Where to, Mac?’ - inspired by the puppeteer getting in a NYC cab on the way to the studio.
The name Oscar, and the personality, were allegedly from a local restauranteur, the proprietor of Oscar’s Salt of the Sea, on Third Avenue, a short distance from Jim Henson’s office, and apparently the owner had a somewhat unkempt appearance and “magnificently rude” demeanour.
The puppet was originally orange, and the original eyebrows are still on the puppet, despite the rest of the puppet changing in the second season to green. This change in colour is even canon in universe as the result of Oscar having visited Swamp Mushy Muddy, a popular fishing spot for Grouches.