More second stage mutations?
 

We now have Rahzar. What would be next

I doubt we'll see too many more, but I wouldn't be surprised if it happens to Spiderbitez since his design is boring and poorly received.

Seeing him turn into an actual terrifying spider creature would be better.

Maybe Fishface as Armaggon?

Though a part of me doesn't want that because I already like Xever the way he is but I think that would be the most likely choice.

I wouldn't want to see it happen to Xever. He's more interesting since it was revealed he doesn't like his fish form, and turning him into Armaggon would remove that bit of character development.

Shredder will mutate into Ch'rell.

Exactly what I was thinking. Besides. I'm getting a little tired of seeing new characters mutate into old ones. (Ex. Timothy into Mutagen Man, Dr. Falco into the Rat King, Dogpound into Rahzar, Spike into Slash, etc....)

I think they should probably keep at least SOME original characters....

I have a good feeling that Fishface will mutate because he might be jealous of Bradford's new form. I don't think we'll see it soon though which would let us see a new character trait for Fishface in that he feels incompetent compared to Rahzar and becomes jealous. I think we'll see Fishface for a bit and later in season 2 he will double mutate himself.

I don't know if they'll call him Armaggon - it sounds too silly personally. I think his new mutant form would possibly be this techno-organic giant fish-monster thing - not necessarily a robot-shark.

hahahahahaha

I think Nick took the direction in bringing in some of the mutants from the 80's show and giving them new and unique origins, instead of rehashing their 80's origins. Also, I personally found the characters you listed to not be that interesting by themselves compared to their mutant counterparts.

This, I just want to see Armaggon in any show. Although I do like fishface, so maybe it'd be better if FF and Armaggon are separate mutants.

I am sure there will be more, as to who we just don't now. Fishface seems the most likely. Maybe Kirby bat mutates into Wingnut?

I wanna see Kirby mutate again "completely" into Wingut!

A bat with a big head is scary and disgusting!

Turn him into some kind of gargoyle-like bat! And if Screwloose appears have them be partners. Make him a guardian angel to April when he seeks to redeem himself for how he treated the turtles.

He's pissed at the Turtles right now for causing the mutation, and even if Donnie does make a retromutagen that will give him back his ability to speak he would be pissed at them. Partially because of the mutation after all it's like "They rescued me from the Kraang only to cause this." and even if he does accept it was an accident, the fact that they had his Daughter out with them and the Kraang would have been enough for him.

But what if the Krang found his hideout, capture him, regain his intelligence with some formula and he escapes again. Only this time bell have his revenge on the turtles.

But April, Casey & Splinter fight him and he escapes again.

He finds the turtles and the Krang together. After a long brutal fight, Kirby was about to fall into the mutagen, by true turtles save hi leaving him confused.

Donnie wishes to redeem himself for what happened. But Kirby slips down leaving Don guilty again.

However, Kirby flies out of the mutagen into a new bat eventually calling GMAT Wingnut. It's like the first form of his mutated bat state was a larva.

I've got a good idea:

Raph encounters a hideous fox-monster at Brad's Dojo. She attacks him and they chase each other around. Then, the true threat is seen; Cockroach Terminator! The two fight the roach and it seems the fox dies. Raph wants to revive her and uses a bottle of mutagen, which is all he has. The mutagen coats her and she become the beautiful Ninjara.

Do you like this idea?

No but only because I am too stubborn to see Ninjara as a mutant.

One thing I have wondered is why is Timothy/Mutagen Man is so different than the other mutants. He can constantly ingest mutagen and it allows him to grow limbs and get stronger. But if another mutant drank mutagen, wouldn't they mutate again the way Dogpound did? And if Mutagen Man fell in a vat of mutagen, would anything even happen?

And also, if only for shock factor alone, I wonder what would happen if Splinter got mutated again,.

This secondary mutation stuff has always intrigued me. I bet we might see one or possibly two more. Hoping Kirby is eventually going to become Wingnut, but not going to bet the farm on that. Was it Cubed that said something about cockroach terminator becoming Scumbug or another dromer? Really loved that notion. However, I'd be more grosed out if it were an everyday joe who mutated into everyone's favorite roach.

Hmm, if Mutagen Man fell into more mutagen, he'd probably see it as a buffet! Sort of sounds like Cookie Monster from hell when he's getting his mutagen fix. I wonder if he'd keep growing more and more tissue and muscle until he eventually started regrowing his flesh and the like? Who knows? He needs to get another episode or two devoted to him so we can find out! I hope he gets to meet April Derp. That boy really needs a girlfriend. What? You know what Queen has to say on the subject, right?

Kirby should be Wingnut when he double mutates. Only when he regains his intelligence in mutant form.

Besides the bat mutant form is incomplete by Kirby's fear.

if anything ends up double-mutating, more then likely it will end up as a ghoulish-looking or skeletal variant of the old form. I have yet to see anything supermutant end up as looking somewhat normal.

It is even possible the rat mutant the Rat King is riding on is Splinter, that could be a second mutation for him for a time.