Azurill

The riverbank is its territory: shallow water, mud and reeds, the waterside habitat it shares with half its evolutionary line. On dry land, it has an obvious problem. Twenty centimetres tall, two kilos, and legs that aren't enough to outrun anything. The solution is its tail, which ends in a blue ball that bounces as if it were made of rubber and carries it around in hops; Pokédex entries insist that this lets it move very quickly, and that it is fond of the lump because it sleeps and plays on top of it.

There is no air inside the ball. There are nutrients: it's the pantry that fuels its growth, which is why it's so disproportionate to the rest of its body. It also doubles as a weapon. Against rivals bigger than it — in other words, almost anything — it swings it from side to side, and if it gets genuinely angry, it attacks with it directly, which is unusual for a Pokémon the Pokédex itself describes as calm. Another entry says it can wind it up like a lasso and snap it out all at once: one Azurill managed to launch itself ten metres that way.

It's the baby form of Marill and Azumarill, and arrived one generation after them. Official category: Polka Dot Pokémon.

Its 190 base stat points are among the poorest spreads in existence, and the spread itself doesn't help: 50 HP, 40 Defence, 40 Special Defence, and a flat 20 in Attack, Special Attack and Speed. It moves last against practically everything and can't survive the exchange.

The only thing that makes it worth discussing is Huge Power, which doubles its Attack. The result is still modest on a base 20, but it turns a baby into something capable of hitting properly with Slam (level 12, 80 power), Bounce (level 15, 85), or Body Slam and Take Down via TM. Aqua Jet, which it gets through breeding, is how it makes up for those 20 Speed with a priority hit. Huge Power is why it comes up in Little Cup conversations; outside that format, there's nothing to discuss.

The other two abilities cover specific gaps. Thick Fat softens Fire and Ice, while Sap Sipper, its hidden ability, nullifies Grass-type moves and raises its Attack when hit by them. The Normal and Fairy combination is sturdier than it looks: immunity to Ghost and Dragon, resistance to Fighting, Bug and Dark, and only two weaknesses, Poison and Steel. Offensively, it's another story, because its Special Attack of 20 wastes Alluring Voice and Draining Kiss, while Normal is stopped by Rock and Steel.

What it can do is the stuff that doesn't deal damage: Charm at level 9 to halve the opposing Attack, Encore, Fake Tears, and Helping Hand from level 3.

It can't be bred. Its egg group is Undiscovered, like any baby Pokémon, so the eggs come from Marill and Azumarill, which do belong to the Water 1 and Fairy groups, and one of the parents has to be holding Sea Incense. Without that item, the egg produces a Marill directly.

The egg takes 10 cycles, around 2805 steps, one of the shortest incubation times in the Pokédex. It produces moves that it can't learn in any other way: Aqua Jet, Perish Song, Belly Drum, Copycat, Present, Tickle, Supersonic, Sing and Soak.

The gender ratio is 75 % female, the reverse of what's usual, which makes it much easier to build your own line. It evolves into Marill when it levels up with friendship at 160 or higher, starting from a base happiness of 70; there's no minimum level, stone or time of day involved, just walk around with it and don't let it faint. Marill becomes Azumarill at level 18. It grows at the Fast rate, so the first few levels come quickly.

In the wild, it's found along the riverbank. Its catch rate, 150, sits in the comfortable part of the table: it's not a 255 like a first-route Pokémon, but a regular Poké Ball at half health solves the problem almost every time. It gives 1 HP EV and 38 base experience.