"Ooooh....who lives in a pineapple under the sea?"
With Spongebob Squarepants, the type of work really varied. It could be animating the photo of a tv anchor fish, keying out the green screen to put Patchy the Pirate, played by Tom Kenny who is also the voice of Spongebob, in Encino to adding CG spit.
One of the things that I did a lot for Spongebob is set replacement. Spongebob backgrounds are actually paintings but when they need to be animated they go through the traditional animation pipeline where they're drawn and inked like traditional cels. It's what I would refer to as the "Scooby Doo effect". It was always easy to see what part of a background was going to move or animate because it didn't match the painted background.Mouse over the image to see the before and after frame.