Wooper

The official category, Water Fish Pokémon, promises something the design doesn't deliver: what's here is an amphibian. A 40-centimetre, 8.5-kilogram axolotl with no arms, standing on two short legs, with a broad beaver-like tail and branching gills sticking out from each side of its head like antennae.

All four Pokédex entries describe the same routine. It lives in cold water and comes ashore to look for food when the afternoon cools down, never in full sunlight. On land, it has an obvious problem—its skin dries out—and solves it by covering itself in a poisonous, mucous film that keeps it moist. It's one of the few Pokédex descriptions where the made-up biology holds up under close inspection: the poison isn't there for show, it's there to prevent dehydration.

It occupies the starting point of two different evolution lines that branch from the same place. At level 20 it evolves into Quagsire; the Paldean variant, which is Poison- and Ground-type, evolves at the same level into Clodsire. Its 210 base stat total, spread across 55 HP and four figures below 46, makes it clear that the species isn't meant to fend for itself.

The spread is 55 HP, 45 Attack, 45 Defense, 25 in both special stats, and 15 Speed. That last figure is the one that matters: it moves last against practically anything, and with 25 Special Defense, any neutral special hit knocks it out immediately.

The only thing that gives it a reason to exist in battle is Unaware, its hidden ability, which ignores the opponent's stat boosts: an enemy with two Swords Dance boosts hits as if it had none. Water Absorb grants it an immunity and healing against Water-type attacks. Damp, the third option, stops the opponent from self-destructing and does nothing else.

The Water/Ground combination helps: a complete immunity to Electric and only one weakness, Grass, although that one hits it for four times the damage. On offense, it covers a fair amount with two moves, Earthquake—which it learns late, at level 40—and Muddy Water, which arrives earlier, at level 28.

It has no place in standard formats: 210 base stats aren't offset by anything. Where it does work is in level 5 formats, Little Cup, where everyone's stat spread is compressed to the same extent and where Unaware turns opponents that spend turns setting up into a solved problem. The plan is the familiar one: Yawn (level 21) to force switches, Toxic (level 36) to start the clock, and Recover—an Egg Move—to hang on until the poison does the work. Against a special attacker that doesn't bother boosting its stats, it still goes down just the same.

It belongs to the Water 1 and Field Egg Groups, two of the most populated in the Pokédex, so finding a compatible partner is effortless. The gender ratio is perfectly even, 50% female, so there's no need to deal with skewed ratios to get the one you want.

Its 20 Egg cycles amount to roughly 5355 steps, a slow egg for such a common species. The egg produces things it can't learn any other way: Recover is the important one, followed by Double Kick and Counter—two Fighting-type moves on a Pokémon with 45 Attack, more curiosity than tool—Curse, Ancient Power, and the trio of Stockpile, Spit Up, and Swallow.

Its evolution has no unusual conditions: reach level 20 and that's it, with no items, no time requirements, and no friendship. Whether it becomes Quagsire or Clodsire is determined by the form it starts from, not by anything the Trainer does.

Its habitat is the riverbank, exactly where the Pokédex entries place it, and its catch rate is 255, the maximum possible. A regular Poké Ball at half health is enough. Defeating it gives 1 HP EV and 42 base experience, the numbers you'd expect from an early-route creature.