Starmie

It weighs 80 kilograms. Nothing about its silhouette gives that away: two purple five-pointed stars fitted one over the other, an outline that looks flat-cut, 1.1 metres from tip to tip. The official category, Mysterious Pokémon, does little to make sense of it either.

What matters is at the centre. Its core shines in seven different colours, which is why it has earned the nickname “the gem of the sea”; some entries say outright that people value it as a precious stone. That same organ sends and receives radio signals during the night, and causes headaches in anyone who gets too close. That is where the rumour recorded by the games comes from: that a body with that shape cannot be from here, and that it came from outer space.

It moves by spinning its star-shaped body like a propeller, which is a very un-starfish-like way to swim. It lives in the sea.

It is the final stage of Staryu's line and evolves with a Water Stone, not by level: there is no age at which a Staryu turns into this. The transformation adds an entire type, Psychic, which its previous form did not have.

The distribution of its 520 points leaves little room for interpretation: 115 Speed and 100 Special Attack out in front, 85 Defense and 85 Special Defense in the middle, 75 Attack and 60 HP bringing up the rear. It is a creature that strikes first and cannot take the counterattack. The EVs it gives when defeated are 2 Speed, which fits the rest.

Natural Cure is the ability that defines it: status conditions disappear when it leaves battle, so a burn or poisoning is cleared by switching out and back in. Illuminate, its other regular ability, does nothing in battle. Analytic, its hidden ability, powers up the move when it attacks last, something that almost never happens with 115 Speed.

Offensively, Water and Psychic have few resistances among the things found in the sea, and TMs cover the rest: Ice Beam and Thunderbolt cover Grass types and Water types that would shrug off Hydro Pump. Recover and Rapid Spin also make it more than just an attacker—it heals itself and clears entry hazards.

The drawbacks are obvious. With 60 HP, any strong neutral hit knocks it out, and its weaknesses to Grass, Electric, Bug, Ghost and Dark are spread all over the place. Against a Dark type, half its offensive repertoire is useless: Psychic cannot even hit it. A Jolteon outspeeds it and tears it apart with its typing.

It has no gender. It has no assigned female percentage, which means its only possible breeding partner is a Ditto, and breeding the line depends entirely on having one with the desired traits.

Its Egg Group is Water 3, the group for crustaceans and deep-sea animals, and it is the only representative there with the Psychic type. Its 20 incubation cycles work out to around 5355 steps, making it one of the slow eggs. It learns no Egg Moves: the list is empty, so everything it knows comes from levelling up or machines.

The evolution leaves no room for nuance: a Staryu exposed to a Water Stone becomes Starmie, with no minimum level, no time of day and no friendship involved. It is worth taking your time over, because the entire level-up move list is learned before using the stone.

It lives in the sea. Its catch rate is 60, in the awkward middle of the table: neither a freebie like the 255 of a route Pokémon nor the wall that is 45, but with 115 Speed and a fragile body, the Poké Ball often arrives after you have accidentally knocked it out. It grows at a slow rate, the most expensive growth curve of all. In the wild, it may be holding Stardust or a Star Piece.