Webster is Oscar's laptop who Oscar told Clamantha was a clam so Clamantha would get away from Oscar ("Two Clams in Love").
Oscar told Clamantha to stay back before she kisses him and covered him with his laptop, and Clamantha liked the laptop. Oscar told Clamantha it was a webcam, then said web-clam. Oscar, finding out that Clamantha is having a crush on the web-cam, said he's Webster the Clam. So Clamantha went out with Webster instead of Oscar. Soon his battery died and Clamantha thought he was ignoring her. She is crying and she has a picture of webster. She loves Oscar now and she hugs. She then threw Webster out of the tank (or a ravine to her) and he was crushed by Wilford the cat ("Two Clams in Love").
Webster will not appear again, due to him being threw out of the tank and crushed by Wilford.