munchlax does not evolve at a sirten lvl it evolves when its friendship is fully maxed out
Munchlax > lvl up with max happiness > Snorlax
level it up
It evolves via happiness
Catch it in FRLG, evolve Munchlax, catch in HGSS or platinum
It evovles with max happiness
You need to get it's friendship to full.
munchlax evolves into snorlax, so snorlax doesn't evolve into anything
he evolves at lv 40 in platinum
LVL 30
Lvl 55
100
It evolves a lvl after you get it