levithan

Something that was never Squidward, is not Squidward, and will never be Squidward no matter how hard you try.

Foolish man: Levithan? You mean... Squidward?
Wise man: Shut the fuck up, motherfucker. Shut the fuck up right now. I will squeeze your fucking teeth if you try to claim that Levithan is a synonym for Squidward.

Levithian

Something that is not Squidward, and should not be mistaken for Squidward

Foolish person: Levithian? You mean Squidward?
Sane person: Shut the fuck up, heathen of the netherworld. I will squeeze your fucking teeth.