What are all the Pokémon who got evolutions in a different gen?

Question

For an example, Sneasel was from gen 2. But, in Gen 4, it received a new evolution and it could become Weavile. So, what are all of the other Pokémon like that?

Edit: I forgot can you also put prevolutions, like Magby and Magmar?

Answer 1

Pokemon that evolve into or from gen 1 Pokemon: Alolan Raichu, Cleffa, Igglybuff, Crobat, Bellossom, Perrserker, Politoed, Slowking, Magnezone, Sirfetch'd, Steelix, Alolan Exeggutor, Alolan Marowak, Tyrogue, Hitmontop, Lickilicky, Galarian Weezing, Rhyperior, Blissey, Happiny, Tangrowth, Kingdra, Mime Jr., Galarian Mr. Mime, Mr. Rime, Scizor, Smoochum, Elekid, Electivire, Magby, Magmortar, Espeon, Umbreon, Leafeon, Glaceon, Sylveon, Porygon2, Porygon-Z, Munchlax

Pokemon that evolve into or from gen 2 Pokemon: Togekiss, Azurill, Bonsly, Ambipom, Yanmega, Honchkrow, Mismagius, Wynaut, Gliscor, Weavile, Mamoswine, Cursola, Mantine

Pokemon that evolve into or from gen 3 Pokemon: Obstagoon, Gallade, Probopass, Budew, Roserade, Dusknoir, Chingling, Froslass

Pokemon that evolve from gen 5 Pokemon: Runerigus
source

Comments

Perrserker, Sirfetch'd, Mr. Rime, Obstagoon, Cursola, and Runerigus all evolved from Gen 8 Pokemon. Galarian forms are different from the original variants. Galarian Mr. Mime doesn't evolve from or into any Kantonian Pokemon.

---

Their pre-evolutions' species were introduced before gen 8, and their pre-evolutions' forms were introduced in gen 8. I think that still counts as a cross-generation evolution.

Answer 2

1st Evolution: Pichu(Gen 2), Cleffa(Gen 2), Igglybuff(Gen 2), Tyrogue(Gen 2), Smoochum(Gen 2), Elekid(Gen 2), Magby(Gen 2), Azurill(Gen 3), Wynaut(Gen 3), Happini(Gen 4), Mime Jr.(Gen 4), Munchlax(Gen 4), Bonsly(Gen 4), Mantyke(Gen 4), Budew(Gen 4), Chingling(Gen 4), Alolan-Meowth(Gen 7), Galarian-Meowth(Gen 8), Galarian-Slowpoke(Gen 8), Galarian-Farfetched(Gen8), Galarian-Corsola(Gen 8), Galarian-Zigzagoon(Gen 8)

2nd Evolution: Slowking(Gen 2), Steelix(Gen 2), Hitmontop(Gen 2), Scizor(Gen 2), Porygon-2(Gen 2), Espeon(Gen 2), Umbreon(Gen 2), Leafeon(Gen 4), Glaceon(Gen 4), Likilicky (Gen 4), Tangrowth(Gen 4), Ambipom(Gen 4), Yanmega(Gen 4), Honchcrow(Gen 4), Mismagius(Gen 4), Gliscor(Gen 4), Weavile(Gen 4), Frolass(Gen 4), Probopass(Gen 4), Sylveon(Gen 6), Alolan-Excutor(Gen 7), Alolan-Marowak(Gen 7), Alolan-Persian(Gen 7), Perrserkerr(Gen 8), Galarian-Slowking(Gen 8), Galarian-Slowbro(Gen 8), Sirfetched(Gen 8), Galarian-Weezing(Gen 8), Mr. Rime(Gen 8), Galarian-Mr. Mime(Gen 8), Cursola(Gen 8), Galarian-Linoone(Gen 8), Galarian-Yamask(Gen 8)

3rd Evolution: Kingdra(Gen 2), Crobat(Gen 2), Bellossom(Gen 2), Politoed(Gen 2), Blissy(Gen 2), Magnezone(Gen 4), Rhyperior(Gen 4), Porygon-Z(Gen 4), Electrivire(Gen 4), Magmortar(Gen 4), Togekiss(Gen 4), Rosarade(Gen 4), Dusknoir(Gen 4), Mamoswine(Gen 4), Alolan-Raichu(Gen 7), Obstagoon(Gen 8), Runegrigus(Gen 8)

Sorry fixed now. That was longer than I thought. Source: https://bulbapedia.bulbagarden.net/wiki/List_of_cross-generational_evolution_families

Comments

This answer is missing some stuff, like Perrserker.