Some Pokémon lose the ability to learn certain moves when they evolve. For example:
- Pichu learns Nasty Plot at level 18, but Pikachu can't learn or re-learn it
- Pichu can be taught Uproar by the Move Tutor, but Pikachu can't
In fourth or fifth generation of Pokémon games (Diamond/Pearl onward), are there any Pokémon who can learn a HM, but lose the ability to learn that HM when they evolve?
Best Answer
Looking through the Bulbapedia learnset entries for each HM move, I have found no instances within each HM set where a Pokemon learn it, but its evolution can not;
There are a few fringe cases that pop up in earlier generations (Mostly between Red Blue and Yellow) where a Pokemon might learn the HM in one game and then be traded to another where its evolution cannot. There may also be unmentioned cases of this between Gens 1 and 2, however the Time Capsule was fairly restrictive in what could be sent back.
*Pikachu is an interesting side case - As there are event and side-game transfers that can give you a Pikachu with Fly, or even Surf (there's also a surfing Pichu). However in none of these instances can Pikachu be taught the moves from an HM.