Yes, strictly speaking these two aren’t part of the same family. But the series tends to treat them as a set, and I have precedence for covering “sets” together, so here we are.
Anyway, Zangoose seems like a very approximate version of a mongoose despite her name and explicit theme. Bright, cartoonish colors, and almost more of a fluffy, west-Asian cat by way of a Looney Tunes villain. I don’t mind it – I prefer it to a lot of the more redundant felines, and cutting too close to an actual mongoose would put us close to well-trod ferret territory, anyway.
I like how they’ve interpreted mongooses’ non-retractable digging claws as “everything about this monster is sharp and grizzly”. It sets her apart from the spiny Sandslash with his similar claws, to boot – Zangoose is really just a lot of material we’ve seen before, but in a way that meshes very well and naturally.
She’s probably my favorite instance of the “anthropomorphized, bipedal animal” template in the series, which we’re going to see a lot more of as time goes on.
He’s still perfectly functional on his own, though – my favorite element by far being the knife on his tail. I really like it as a more aggressive replacement for a warning rattle, and as a way of making both ends of the snake dangerous. Plus, I bet it lets him and Zangoose get into “knife fights” on the regular, explaining why they have matching jagged scars across their bellies Clever.
The other bit that’s nice here is the big ol’ scales on this lizard, which gives him a nice and textured look that he’d feel a bit limp and noodly without. I’m less keen on the fact that they form “feet” along his belly – maybe they’re meant so he can get better traction to stand his ground in a scuffle?
Eh, Seviper is fine, I just don’t know that we need him outside of his specific context.
Both of these are fine main-game monsters, though. Zangoose is your classic, Normal-type glass cannon – with a properly-focused attack spread – while Seviper sacrifices its speed for a more mixed attack. Attack-forward poison-types are an odd business, but Seviper has the kit to make fairly good use of it, at least. I do wish that they were a bit more symmetrical – like Zangoose preying on Seviper’s lower defense and Seviper likewise targeting Zangoose’s lower special-defense, but hey – neither is exactly a deadbeat.
The big pull with these two is that they’re a reflection of how, in the real world, mongooses and snakes are squared against each other as “rival” animals. And, in a not-so-fun twist, some of that is rooted in biology, and some of that isn’t.
Mongooses are one of the few real-life animal families that are properly resistant to snake venom – as Zangoose is via its passive ability. This lets them be an unabashed hunter of snakes that otherwise could scare off prey above their weight class.
The bit where it’s an enforced rivalry is partly up to folklore and The Jungle Book (the actual book, not any of the movies), and partly up to people capitalizing on those stories. In some cases, mongooses were deliberately imported to fix snake over-population – and had the same repercussions as any other time humans bring in invasive species. In other cases, snake-mongoose fights were used as part of traveling entertainment acts, basically letting nature set up a cockfight for them.
It’s kind of an uncomfortable parallel for the series, given that one of its main excuses to justify its creature-on-creature violence has always been “Pokémon enjoy scuffling to begin with; trainers help them get stronger at what they’d otherwise do naturally”. That said, while you can domesticate a mongoose or a viper, I doubt they’re treated nearly as well as we see in the series. Not that it makes it totally okay, but that the “okay-ness” of any of these is on a steep, precarious sliding scale.
I really like Zangoose, and how well this pair plays off each other when it ties back to the series core conceit. The real stinker is that I wouldn’t want to see Seviper in a game where we already have Arbok, since two snakes are a bit redundant even if one has a more focused purpose. That puts the two into a space where I’d Reserve them for when we don’t even have Arbok already.
Any and all appreciation for Zangoose and Seviper is welcome in the comments!