which of the following non humanoid killers would you most want to see in DBD?

A robot can be humanoid, so there's still potential of getting a Killer Robot.

I think a spider killer would be cool.

Giant Spider is honestly the least likely thing to be made. Devs stick to human / once-human / humanoid characters pretty exclusively, but the "Giant Spider" is such a classic pick that harkens back all the way since when DBD released that I couldn't help but pick it for the purposes of this poll.

I just want them to actually update the Minotaur legendary skin and give it the same treatment legendaries are getting nowadays. As it stands, I think it's pretty low quality by comparison, why does the Minotaur still sound like a rage filled Samurai warrior? Why does the Greek Minotaur wield a Japanese Kanabo? I'd love to see the character make fittingly inhuman sounds which befit an actual minotaur, and wield a Labrys which is fairly iconic to the myth and culture of the original legend.

Undertale (I'm assuming Undyne being the Undyne from Undertale) is probably one of the least fitting licenses out there, it's cutesy style and tone is far too divergent from Dead by Daylight. Sure they're "monsters" but for most of them, save a few, they're monsters in the same way that Pokémon are "monsters" and it just doesn't work. Undertale has it's dark moments, "brother-killer" and all that, but for the most part it is far too light hearted for Dead by Daylight, hence the bone puns and jokes about Spaghetti.

Still waiting on the T-1000 from Terminator. I think the liquid metal android would be extremely unique even as far as mechanical inhuman characters go, and would diversify the killer roster quite a bit. Plenty to work with as far as powers go toward a kit, would have a really interesting M1 with knife arms or other classic slasher instruments, and if a shapeshifting power was ever going to exist in Dead by Daylight the T-1000 would be my 2nd pick to give it to (obviously John Carpenter's The Thing would be 1st pick). Hell, I'm half expecting a fnaf animatronic to come eventually, so if they did make an original robot character, it'd have to be pretty unique from either of those franchises I think.

In which case if you're talking about the mythical creature it's spelled Undine or Ondine, not Undyne - because the latter is the character created by Toby Fox. A google search will ONLY bring up Undertale if you search up "Undyne" so I don't feel as bad for misinterpreting, since it was the result of a typo on your end.

Equally my point still stands, I don't see what kind of place a Water Nymph has in Dead by Daylight.