Over the years Oscar the Grouch has had many pets. His diverse menagerie includes various dogs, a cat, a pig, several elephants, and a donkey. His favorite pet is his worm, Slimey.
- In Episode 0793, Grover offers to become Oscar's pet, however it doesn't work out.
- In Episode 1449, Oscar tells Telly and Susan that he has a whole flock of moths in his can, which he gives holeless shirts to munch on.
- In Episode 1740, he mentions he has hippos in his can (who reside in his swimming pool).
- In the Elmo's World installment on Farms, Oscar reveals that he has an entire farm in his trash can.
- Similar to a pet, Oscar builds Charles the Robot to follow his every command.
- Stinky, a seagull later seen in Episode 3132
- Moby Jane, a whale mentioned in Episode 2269
- Portia, a rhino