What animals haven't been turned to mutants yet?
 

Across every series, what animals have never been mutants in the TMNT franchise?

I would have said elephant, but then I forgot about Doctor El from the Playmates toyline. Then I remembered all the others like King Lionheart and all the random Archie and Playmates mutants who were never in the shows.

So what haven't they mutated yet?

There has never been a beaver, polar bear, snail, raccoon, gopher, goldfish, porcupine, leech, jellyfish, penguin, cow or grasshopper.

And since plants are now up for grabs, I would love to see a Cactus mutant, personally.

Mutant scorpion. Mutant tasmanian devil. mutant woodhuck. mutant otter. mutant seal. mutant stinkbug. mutant earthworm (Groooovy!!). mutant ladybug. mutant butterfly. mutant crab/lobster

Over a million different species!

But in terms of popular animals: Zebra, Snail, Crab, Deer, Hippo, Starfish, Whale, Dolphin, Seal, Horse, Cow (That was a bull in "Mutagen Monster"), and so much more.

Then you have some animals that have been created by fan members via RPGs: Lion, Tiger, Salamander, Jaguar, etc. That leaves plenty of ideas for mutant making!

Wild Boar, Mouse, Mosquito, Snail, Snake, etc.

Flying squirrel.

Fox.

Ferret.

Owl.

Hedgehog, because somebody might get sued.

We have a Polar Bear and a Fox lol both are snow themed. Alopex is the fox but for the life of me I can't remember the Polar Bear form TMNT 2 NES.

A lot of the animals mentioned, like Beavers and Cows can be created in the RPG
Porcupines appear in both the RPG and the first video game
Leech, Bloodsucker in the Mirage comics
Otter's can be created in the RPG.
Mouse, Monty Mouse
Snake, appears in the Fred Wolf series "snakes alive" episode.
Fox, Alopex in the IDW comics
Ferret can be created in the RPG
Owl, appears in the Archie comics
There was no Polar Bear, Tora was an alien and he was modeled after a wolf not a bear.

Ninjara in Archie is a fox.

The comic that had April become a turtle had a Mutant flying squirrel. And it seems we're getting an owl mutant in season 2.

Beaver Mutant: in TMNT and Other Strangeness Roll Playing book.
Polar Bear Mutant: TMNT arcade game for nes (and yes he is a bear).
Snail Mutant: Drawn by Peter Laird for the 80s toy line but never produced.
Raccoon Mutant: TMNT & Other Strangeness Roll Playing Book.
Porcupine Mutant: TMNT & Other Strangeness Roll Playing Book.
Leech Mutant: Blood Sucker from the Mirage Comics.
Jellyfish Mutant: From the Mona Lisa Episode of the 80s toon.
Cactus Mutant: From the Archie special issues.
Some of those animals I believe are shown in the TMNT and Other Strangeness book.
Mutant Earthworm: Bookworm From the Archie Comics.
Mutant Crab: We saw generic mutant crabs in the 2k3 cartoon.
Mutant Lobster: From the TMNT magazine comic strip.

Most species, I suppose.

Hare (Usagi is a rabbit)
Mantis
Sea Turtle
Mouse
Crab (sapient)
Toad
Tree Frog (I presume Genghis Frog is not a toad or tree frog)
Wasp (sapient)
Weasel
Civet
Genet
Mongoose
Echidna (Knuckles was not present in Fight For The Fox Box)

Technically rabbits are still up for grabs, since Usagi isn't a mutant and isn't even a TMNT character. He's a crossover character from his own seperate series. Sadly most TMNT fans don't know this and he might as well be considered a TMNT character by now that if IDW/Nick were to create their own rabbit mutant, fans would consider him a 'poor man's Usagi'.

She's not a mutant.
Again he's an alien not a mutant, and he looks more like a snow wolf than a bear.
White Rabbit from the RPG.
Weasels appear in the RPG.

Nope, that was definitely a polar bear. He was big, white, and had a STUBBY tail and ROUND head and ears. And alien or not, he was still an anthro bear.

Alopex was definitely a mutant so foxes have been done, even if ninjara wasn't technically a mutant. Neither was Jagwar, IIRC, but he could be counted, I suppose. (Son of an animal spirit/god? Still counts, IMHO.)

And there are thousands of species of birds, insects, lizards, fish, and yes, even plants that have never been mutated. When one considers the number of animal species on Earth, the list of what HAS been mutated is actually very small. Like kangaroo rats, for example- there's never been one of those. (And they're not "true" rats like Splinter, so yes, it counts as never being done.)

A snake mutant would be scary. Especially if it's a cobra given it's rather intimidating head piece or an anaconda for it's sheer size.

Wrong, Tora was a polar bear.

Look up Scaletail.