I would really love a snorlax but I accsadently made the one in front of the tunnel faint and I cant find another one anywhere else!
If you can manage to beat the Elite Four for the second time, then Snorlax will respawn in Vermillion, and be back where it was before for a rematch!
Unfortunatly no you have to trade for one or evolve a munchlax. You
can get a munchlax from the pokewalker but it is one of the hardest
to find on the hardest to get route.
If you have Diamond, Pearl, or Platinum you can get a Munchlax from a Honey Tree, then evolve it. If not, GTS seems like the best option.