Zester and Shredder are the secondary antagonists from the Sesame Street themed Universal Studios ride Spaghetti Space Chase.
Zester and Shredder are the two cheese graters and the henchmen of Macaroni the Merciless. They helped Macaroni steal all spaghetti around the world. In the ride, Sesame Street is loosing spaghetti. On people's bowl, the spaghetti are floating away. Super Grover and the audience will go to space. In Macaroni's lair, Zester and Shredder are shown to tie Super Grover with spaghetti to prevent him from stopping their boss. Later, Zester, Shredder and Macaroni got defeated by a bunch of Sesame Street Superheroes.
Zester and Shredder look like each other. The differences are the helmets, which have different bottom holders, facial expressions, and the sleeves. It is possible that they are brothers.
They both have similar personalities. They serve their master. The differences are probably Shredder is the tougher one based on his facial expression and sleeves.