With some exceptions, most Pokemon that evolve will evolve by level up.
leveling him up
By leveling it up.
By leveling up.
Leveling up
By leveling it up.
cloyster doesn't evolve into any Pokemon. You can evolve it from Shellder but with a water stone rather than leveling up.
That depends on the type of Pokemon that is leveling up.
by leveling up to level 18, it will evolve into croconaw
It evolve by a moon stone not leveling up
it doesnt evolve by leveling up its by filling up its happiness.
by leveling up to level 78
Dragonair can evolve into Dragonite by simply Leveling up to Lv.55.