Walk: Pokéwalker
Its base catch rate is 50 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Moon Ball, Heavy Ball or Nest Ball.
Evolution: Munchlax → Snorlax.
Munchlax in every game · Pokémon HeartGold & SoulSilver interactive map (Johto & Kanto)