Squilliam FancysonIII is Squidward's arch-rival whom he met in high school band class. He is a very wealthy, snooty, unibrow-endowed octopus who has succeeded in everything Squidward has failed in and thus looks down upon him. Squidward is painfully jealous and constantly attempts to show Squilliam he's not a loser, with varying results. Like other octopus characters, Squilliam's character model is nearly identical to Squidward, but he has a unibrow and he wears a fancy maroon robe. He owns a private yacht, a private lake, a private heliport, a private island, and a balloon/casino. He owns a fancy house which made an appearance in "House Fancy." Squilliam is voiced by Dee Bradley Baker.
Squilliam is an octopus with six tentacles. He wears a red and black robe and has an ascot. Squilliam has a large black single eyebrow, or unibrow. He has had it in every episode. In "Band Geeks," he shows pride in it when he calls it "big and valuable." In "Professor Squidward," this feature is how the police told him apart from Squidward. In "House Fancy," Squilliam has a large replica of his unibrow that was made of 500 solid gold painted doorknobs.
Squilliam's first appearance was in this episode. He challenges Squidward to play his band at the Bubble Bowl, as his own band could not make it. However, at the end of the episode, Squilliam arrives at the Bubble Bowl anyway to watch Squidward fail (which may imply that he was just setting up Squidward to make a fool of himself), but upon seeing the band's surprisingly good performance, Squilliam appears to have a heart attack and is rushed to the hospital on a stretcher.
Squidward tells Squilliam that he is the owner of a five-star restaurant in an attempt to show him up. Although Squilliam is initially impressed by SpongeBob's new found fine dining expertise, Squidward is ultimately humiliated when SpongeBob cannot remember his own name and goes insane and destroys the restaurant.
Squilliam's ridiculously luxurious house is featured on the TV show of the same name. The house features, among other things, a golden toilet, an elevator with a built-in hot tub, and a massive sculpture of his unibrow made entirely out of gilded doorknobs. Squidward's jealousy once again gets the better of him when he calls the show's host, Nicholas Withers, claiming that his house is better than Squilliam's. Although Squidward's house is destroyed as a result of his attempts to make it fancier, Withers sees his destroyed house as a work of art and proclaims it to be better than Squilliam's. Squilliam breaks down and falls over, in tears, as he is once again upstaged by Squidward.
Squilliam also appears at the end of "I ♥ Dancing," where, after Squidward is given the part of a line dancer for Squilliam, he begins to abusively train him in the same manner that Squidward did to SpongeBob.
In an alternate universe, main universe SpongeBob and Patrick walk by him putting up a sign in Bikini Bottom when Man Ray took over.
Squilliam is rich and fancy. He acts more mature than Squidward, but makes no secret of the fact that he considers himself superior to others due to his enormous wealth. He is a mean, selfish, sadistic, and arrogant jerk who takes great pleasure in asserting his perceived superiority over middle-class citizens like his arch-rival Squidward. He also speaks in a very mocking tone, placing great emphasis on his low regard for Squidward and an equally large amount of inflated praise in his lavish lifestyle. Even though he's a jerk, he somehow makes friends easily, probably for letting people in his private jet, yacht, balloon/casino, etc.
Like Squidward, Squilliam is narcissistic and he considers himself to be undeniably handsome, even though he and Squidward (and every other octopus) look alike.
Squidward and Squilliam absolutely hate each other because Squilliam brags about everything he succeeds in to Squidward (Which Squidward usually fails in) and is always mocking him for being of a lower class.
Squilliam is seen to like having SpongeBob around. The most likely reason for this is because SpongeBob's antics usually end up making Squidward look bad, even though he doesn't mean to do that. SpongeBob shows respect for Squilliam as well. The two have a good friendship and have never had any arguments in the series.
"Sounds as though you've got a dying animal to attend to, eh old chum?"
"I'm filthy stinkin' rich!"
"It's a gilded doorknob."
"Come on everyone; let's go take a ride in my balloon slash casino!"
Squidward: "Oh no, he's hot!"
(referring to his unibrow) "It's big and valuable. I'm a leader of a big fancy band right now. And we're supposed to play the Bubble Bowl next week."
"Squidward Tentacles has the fanciest restaurant in Bikini Bottom, and he does not suck eggs (After Squidward tricks him into thinking he actually does own a 5-star restaurant)."
"Explain what? That you, Squidward Tentacles, voted most likely to suck eggs in high school, (walks into Krusty Krab) are trying to pass off a lousy burger stand as a five-star... (Gulps) ...restaurant!?"