Blissey

Gold and Silver handed out new evolutions among several of Kanto's rarities, and Chansey got one that depended not on level but on affection: level up with high friendship, and that egg with legs grew to 1.5 meters tall. The second generation introduced it that way, with no stone or trade involved.

That gives us a 46.8-kilogram creature with hair parted into two halves that fall like an apron, and a pouch on its belly where it keeps an egg. The egg isn't offspring; it's food. The Pokédex entries keep coming back to the same points: the eggs it lays are full of happiness, a single bite calms «even the fiercest of Pokémon», and precisely because of that they «fetch exorbitant prices». Some people even quote prices for them.

Its silky fur works as a sensor. It senses sadness in people and Pokémon, approaches anyone who's having a hard time, and shares a Lucky Egg to bring a smile back to their face. The official category, Happiness Pokémon, leaves little room for interpretation.

The line took longer to be completed from below: Happiny didn't exist until the fourth generation, so for two generations this was a duo rather than a trio. The pink color, humanoid shape, and urban habitat are shared by all three.

The spread is one of the most extreme in the entire Pokédex: 255 HP—the highest figure in existence, shared with Chansey—, 135 Special Defense and, on the other side, 10 Attack and 10 Defense. The 540 total points are almost entirely invested in taking special hits and nothing else. Its Speed, 55, only serves to make it move late.

Natural Cure is the ability that holds the whole thing together: when it switches out, any status condition disappears. That turns poison, burn, or paralysis into a temporary inconvenience and lets it come back in clean as many times as necessary. The alternative, Serene Grace, doubles the chance of secondary effects, which is of limited use here because the moves it can afford to run are few. Healer, its Hidden Ability, only makes sense in Double Battles.

With 10 Attack, the damage has to come from somewhere else, and it comes from Seismic Toss, an Egg Move that removes HP equal to the user's level without looking at any stat. Soft-Boiled, learned at level 44, restores half its HP. Heal Bell clears the entire team. Thunder Wave and Stealth Rock round out its toolkit for getting in the way.

What holds it back is obvious. Ten Defense means that almost any decent physical attack cuts it in half, and its Normal typing leaves it weak to Fighting, with Focus Punch and Focus Blast spread everywhere. Ghost-types such as Gengar are immune to Seismic Toss and any other Normal-type attack, so they switch in for free and stay in.

It belongs to a single Egg Group, Fairy, and is 100% female, so breeding requires a male from that same group or a Ditto. The egg doesn't hatch into another Blissey; it hatches into Happiny, the baby stage.

The 40 incubation cycles amount to about 10,455 steps, among the longest stretches there are. Its four Egg Moves are Seismic Toss, Heal Bell, Present, and Gravity; the first is what justifies the effort, because without it the offense drops to zero.

The chain has two different conditions, and neither involves leveling up alone. Happiny evolves into Chansey when it levels up while holding an Oval Stone, and only during the day. Chansey evolves into Blissey when it levels up with friendship at 160 or higher. The curious detail is that the Oval Stone needed for the first step is held by wild Chansey and Blissey, along with the Lucky Egg.

Its habitat is urban, and its catch rate, 30, is among the tough ones: below the usual 45 for starters, combined with 255 HP that makes it almost impossible to leave it in the red without knocking it out. It makes up for that with a fast growth rate and 3 HP EVs per defeat. Its base friendship, 140, is well above average, which shortens the path to the 160 required for evolution considerably.