What pokemon can learn headbutt by leveling up?

There are no Pokémon that can learn Headbutt by leveling up. Headbutt is a move that can only be learned through:

* TMs: There are no TMs that teach Headbutt.

* Breeding: Several Pokémon can learn Headbutt by breeding with a parent who knows the move.

* Move Tutor: Some Pokémon can learn Headbutt through a move tutor.

To find out which Pokémon can learn Headbutt, you can use resources like Serebii.net or Bulbapedia, which have comprehensive lists of all Pokémon moves and their learning methods.