Kabutops

The horseshoe crab has gone hundreds of millions of years without changing shape, and that accounts for half the design. The other half comes from eurypterids, the sea scorpions that hunted in Paleozoic seas: hence the scythes instead of hands and the upright stance, which no real horseshoe crab has.

The Pokédex entries insist on two things. One is its speed in water: it folds its limbs against its body to become compact and moves its shell to propel itself, and one entry even gives a figure, 29 knots. The other is how it eats. It does not chew. It holds its prey, tears it apart with its sharp legs and sucks out its vital fluids, a description repeated in almost the same words across several generations.

There is also a piece of natural history hidden in the entries themselves. Its legs and gills show a half-finished adaptation to life on land, a transition that began but was never completed because the species went extinct first. At 1.3 metres and 40.5 kilograms, it is the final form of a two-stage line, evolving from Kabuto at level 40, and it shares its category — Shellfish Pokémon — with its pre-evolution.

The 115 Attack and 105 Defense are the two figures holding everything else up. With 60 HP it cannot take much punishment, its 65 Special Attack and 70 Special Defense leave the special side with nothing to work with, and its 80 Speed falls just short of what it would need to outspeed anything that matters. That is why Swift Swim is the Ability that determines the whole approach: in rain, that 80 is doubled and the problem disappears immediately. Battle Armor only blocks critical hits. Weak Armor, its Hidden Ability, raises Speed at the cost of lowering Defense whenever it takes a physical attack, and with 60 HP that trade is expensive.

On the attack, Rock and Water overlap very little: few types resist both at once. Stone Edge arrives at level 70 with 100 power, Liquidation at 56 with 85, and Aqua Jet at 15 provides priority to finish off whatever is left standing. TM Swords Dance doubles its Attack in one turn, and the same rain that gives it Speed also strengthens its Water-type moves.

Defensively, it is a different story. The combination leaves it with a quadruple weakness to Grass and three more to Electric, Fighting and Ground, all of them common across any normal team. In return, it resists Fire, Ice, Normal, Poison and Flying. The turn it spends setting up rain or Swords Dance is the turn when its 60 HP is left exposed.

Its Egg Groups are Water 1 and Water 3, the second shared almost exclusively between marine fossils and shelled creatures, so the list of compatible partners is short. The gender split is lopsided: 12.5% female, or one in eight. Since the species does not appear on routes, getting that female means reviving fossils until one appears or relying on a Ditto.

Its 30 Egg Cycles are among the longest assigned to an ordinary Pokémon. Using the usual formula, (30+1)×255, that works out at roughly 7905 steps, more than twice as long as an initial-stage Pokémon takes. It has no Egg Moves, so breeding is useful for Nature and IVs and not much else.

The evolution has no unusual conditions: Kabuto reaches level 40 and that is it. No stone, no held item, no trade, no time of day. Its growth rate is Medium Fast, the most regular of the six, so level 40 arrives when it should.

Its catch rate is 45, the figure for a Pokémon that is difficult to catch, although in practice it is never caught: the habitat assigned to it by the Pokédex is the sea, and it cannot be found there. It is obtained by reviving the Dome Fossil, which in Mt. Moon means giving up the Helix Fossil for Omanyte.