If you haven't figured it out yet, Spongebob is completely made up but for a good reason. The life of a real sponge would be too tragic for children to watch.
A few years back Spongebob introduced a whole lot of us to an up-and-coming deathcore band by the name of Job For A Cowboy and now he's returned to school the young 'uns on the brilliance of the late, great Chuck Schuldiner by covering Death's "Misanthrope".