Quoted By:
Hypothesis: Pokemon in Cerulean Cave and Victory Roads are non-native/introduced.
Victory Roads are specifically designed to challenge all comers. As the league has developed the area around and within Victory Road, it isn't a stretch to suggest they've imported tough, powerful, and dangerous Pokemon.
As for Cerulean Cave, there is obvious non-natural manipulation to the local species, as Raichu and Wigglytuff are "native", even though they evolve from elemental stones. This is easier to explain away though, as Mewtwo likely summoned and augmented the species living in the cave with his Psychic powers.
So, iirc, that means Rhyhorn is native to Sinnoh, and Lickitung is native to Johto or Sinnoh. At least.
