The complete Pokemon RBY pokedex, part 14

Pokémon Name: Snorlax
Type: Normal
Classification: Sleeping Pokemon
Pokédex Number: 143
Ability: Immunity and Thick Fat
Dream World ability: Gluttony
Useful Attacks: Rest
Location Found:
D/P/P: Evolve Munchlax
HG/SS: Route 11 (in-game event)
B/W: Evolve Munchlax

The picture pretty much says it all, right?

Evolution: From Munchlax via Happiness