So did anybody see this one coming? I know I didn’t. I think we’ve managed to get quite a few surprises in the past couple years, but there really hasn’t been a choice as left field as Cottonmouth. The Serpent Society is a niche group as it is, so when you add the relative nichiosity of that snake-themed supergroup to the fairly lower-tier recognizability of Cottonmouth, you’re several shades past A-list.
Ain’t it great?
I’m not even going to examine the why of it. The fact is, they made somebody as relatively obscure as Cottonmouth, and this is a fact that needs to be celebrated, not questioned. His debut has sparked a marked increase in interest over the Serpent Society, a group that I will admit I doubted would ever get any consideration outside of possibly Cobra or Diamondback, the two higher profile characters connected to the Society. But with Cottonmouth, it’s almost like any member is fair game. Will they pursue this line further, or is this a one-and-done rarity? Who knows. Whims and wishes are all we’re left, so let’s just deal with the facts.
I’m going to ask you to put up with a little hypocrisy concerning my review for this figure. First off, I will say I have some scale-nazi tendencies. While I’m not sitting there like a crazy person measuring my figures down to the picometer, I do like a certain scale correlation to how I see the figures. It’s this line of thinking that makes me see the Absorbing Man BAF as larger than I’d like, and all the Hasbro Thors and the Wrecking Crew as too big and won’t allow me to use the Marvel Select Juggernaut as my main Juggernaut.
So bringing this around to Cottonmouth, yes, technically he’s too big based on the majority of his appearances. The new, mid-sized Grim Reaper body would have been perfect for him. But the powers-that-be at Hasbro decided that he would be on the larger body. And while you can find images of him looking larger (like, one image where he looks larger, that is) he is often portrayed as much leaner than the Hyperion-sized body would have you believe.
I can’t bring myself to care.
Would I have preferred him on the Grim Reaper body? Of course. But I’m setting that aside. And I think anybody who is interested in lower-tier characters should set aside their qualms as well. Character choices like this need to be supported, and not buying him because he’s too big sends a wrong message. It’s not saying “You made him too big”; it’s saying “We don’t want this character.” Never tell Hasbro that, they won’t learn the right lesson.
So yes, he’s too big. I’ll tell you the same thing I told myself: get over it and be happy they’re acknowledging the C-list, or D-list, even.
Taking all that into consideration, you’ve basically got the Sabretooth body complete with the clawed hands, so you know what to expect with all of that. The only new piece is the head.
The head itself is well done with a malevolent grin and smirky face seated in a snake-head helmet. It’s simple but has a lot of character. Now, this was clearly one of the cheaper-to-accomplish offerings in the wave, so there’s not a lot of extra going on here. You get one figure and one Build-a-Figure part. An extra head showing off his snakey super-power — Cottonmouth expands his mouth, unhinging like a snake, to bite your face off, which is creepy as hell — would have been welcome. 
If we had the option of only getting one head, it’s a tough choice between powers-on or powers-off. I’ve never been a fan of screaming heads, and I tend to like my figures to be neutral, but I can definitely see the benefits of the biting head. They clearly only had the budgetary leniency to do one head for this figure, as they’ve usually been good about alternate heads and hands. This is a scenario where it will be the right choice for some, and the wrong choice for others. I can see how the expressive biting head might have sold some people who were on the fence on the character.
So basically you’ve got a simple, stripped-down figure easily accomplished on a ready-made body that fills out a hole you might have never known you needed filling until now. To me this is the brightest spot of the base-body system Marvel Legends has going now: a head and a paint job and you’ve got a brand new character, unexpected and welcome.
Cottonmouth is available as part of the red Onslaught Series at Big Bad Toy Store here or here