Why are SpongeBob's parents cookies but he's a sponge?

No they just look that way. but they are a round type of sponge...i guess that's what happens to old sponges...lol

Spongebob's parents are regular sea sponges, himself is a sponge you may find in a kitchen. How his parents managed to have a kitchen sponge son, I do not know.... Well, it's just a cartoon, anyway!