Jigglypuff evolves when exposed to a moon stone.
It doesent evolve through levels, it will only evolve to jigglypuff through high friendship, use a moon stone on the jigglypuff to evolve it to wiglytuff.
i used it to evole my clefairy in to a clafable and my jigglypuff in to a wigglytuff
in platinum what leve does staravia evole
Level 24
level 40
at level 48
level 1
at level 36
Level. 2
level 14
It evolves at level 42.
level 28 or level 29