Squilliam Fancyson is the single number one hardest thing to kill in the entire UnUniverse (except for the five Undefeatables, Weegee, WaPo, and maybe a few other guys). His greatest achievement in life is pissing Squidward Tentacles off over and over. He also likes eating birds, because he is Evil!
Unlike Squidward, Squilliam does not, I repeat, does NOT suck eggs. However, Squilliam doesn't own a five star restaurant (he thinks Squidward does, but Squidward is the cashier, because he didn't go to college). He also helped create Bob The Builder's shames, because he is awesome like that. This is what makes them so popular.
He works for the evil BBB as a terrorist and evil god. He is also known to be an expert at Pokemon (he has one Babypea). He is also the most powerful sea-creature in the UnWorld, as he can breathe on land, and Blow Stuff Up, which most fish can't. Squilliam has a pool made of solid gold, because he is a moron.