Slowpoke in depth
The hippopotamus that fishes with its tail
The main reference for the design is a cross between a hippopotamus and a giant salamander, with the sea otter as a third reading because of its aquatic life and its relationship with shellfish. The bit about the tail falling off and growing back is not made up: autotomy and regeneration are real processes in lizards and salamanders, taken here to the extreme of the animal not even noticing.
The English name is the word itself — slowpoke, an American colloquialism for someone who moves slowly. The Japanese name is better constructed. ヤドン (Yadon) combines 宿借り yadokari, the hermit crab; 宿主 yadonushi, the host carrying a parasite; and 鈍 don, blunt or clumsy. It can also be read as a shortened form of ヤドラン (Yadoran), the Japanese name for Slowbro. Whichever route you take, the Japanese name announces the Shellder that will eventually bite its tail before that Shellder has even appeared.
Fifteen points that have not moved since 1996
The stat distribution is still the same as in Red and Green. The only thing that changed was the split of Special that the second generation applied to the entire Pokédex, which divided its 40 into two identical forties: it gained nothing and lost nothing. It would take until the fifth generation, with the arrival of Regenerator, for there to be a real reason to bring it into battle.
There is one first-generation detail people forget: in Red and Blue, the menu icon changed upon evolution in only three cases, and this was one of them, along with Magikarp and Rhyhorn. It is also the only Pokémon whose two evolutions give different Effort Value distributions when defeated.
The tail, a product
Few species have an entire industry built around them. In Alola, the tails are dried and boiled in salt water as a home-cooked dish; in Galar, they are smoked and sold packaged as a curry ingredient. In Johto, things were murkier: at Slowpoke Well, beside Azalea Town, Team Rocket cut them off to sell on the black market at high prices, despite the tail having no nutritional value. The fact that it grows back painlessly is precisely what makes the business possible, and the Pokédex describes it with an indifference that is more uncomfortable than any moral lesson.
Losing a type on the way to Galar
The Galarian variant is unique across the entire series: it is the only Pokémon whose regional form loses a type without gaining another in exchange. It remains pure Psychic, with Water removed, and the rest of the distribution unchanged — including the same 15 Speed. It is also the only Pokémon with a regional form belonging to a branched evolution line, and its two Galarian branches end up sharing Poison and Psychic with each other but not with the form they evolve from.
The story reason is diet. Galarian Slowpoke eat Galarica Seeds, which is why their tails taste spicy instead of sweet. Those same seeds, braided together, form the Cuff and the Wreath that trigger the two evolutions. There is only a tiny difference in their moves: Galarian Slowpoke learns Acid at level 6 where Kantonian Slowpoke learns Water Gun, and little else.