Usually, humanoid implies some semblance of human appearance, but the wiki page specifically calls out "Animal head, object head, and other creatures with non-human heads on human bodies," and if Cthulhu isn't a a dude with an octopus for a head, then I don't know what is. That being said though, you've got characters like Moreau here, whose literal purpose is to be an anthropomorphized octopus, and he's virtually identical to a lot of Cthulhu depictions.

So is Cthulhu (and mind flayers for that matter) a humanoid, or an anthro, or both? Should Moreau be classified as a humanoid? Looking at the posts, there really seems to be no rhyme or reason to how people are tagging posts like these.

I'd say Cthulhu is a humanoid, as he's not an anthropomorphized version of some real or mythological creature, but rather his own thing that happens to have a vaguely human shape. Moreau there, on the other hand, looks to be a version of an octopus made to look more human, i.e. an anthro.

questions that would make h.p. lovecraft roll in his grave

vulpes_artifex said:
I'd say Cthulhu is a humanoid, as he's not an anthropomorphized version of some real or mythological creature, but rather his own thing that happens to have a vaguely human shape. Moreau there, on the other hand, looks to be a version of an octopus made to look more human, i.e. an anthro.

I'm not a big fan of that definition, it'd exclude any species that are completely unique but still have regonizable anthro traits (i.e. they're covered in fur or scales). I've always tagged Cthulhu as an anthro anyway, he's an octopus thingy

if the character has overwhelmingly animalistic features, and (outside of being bipedal and maybe having tits) lacks most human features it should not be tagged humanoid, even if those animalistic features aren't 1-to-1 features of actual animals.

strikerman said:
questions that would make h.p. lovecraft roll in his grave

I'm not a big fan of that definition, it'd exclude any species that are completely unique but still have regonizable anthro traits (i.e. they're covered in fur or scales). I've always tagged Cthulhu as an anthro anyway, he's an octopus thingy

Well, considering creatures like Twili Imps and Gardevoir are considered "not furry", I think we've already gone pretty far down that road.

vulpes_artifex said:
Well, considering creatures like Twili Imps and Gardevoir are considered "not furry", I think we've already gone pretty far down that road.

gardevoirs and Midna don't really have any animalistic features at all. they're not too much diffrent than an elf or goblin

Cthulhu just looks like a real big octopus grew a torso with arms, legs, and wings. you can't really get much more anthro than that.

Cthulhu is not typically portrayed with human skin, generally that of cephalopod, reptile, or fish. In addition to usually having wings.
If animal head+animal skin+secondary features is disqualified due to being a plantigrade biped, guess it's time to tag every Star Fox character as a humanoid, right?

Mind Flayers are more of an edge case as they come from humanoids, they're parasites that have fully consumed the host. I believe their typical anatomy diverges (Dissection) from the typical humanoid host about as much as a gray alien does, asides from the head. The issue is that Illithids can come from a lot of things, much like Xenomorphs, and do retain holdovers from their hosts (brainstealer dragons come to mind) so the degree varies. There are also "covert" permutations that retain an otherwise outwardly human appearance and are just different inside. Mind Flayer isn't a "species", asides from the tadpoles and neolithids, any more than a cyborg or vampire is a "species".