Acid Armor

Acid Armor (とける, Liquefy) is a non-damaging Poison-type move introduced in Gen I.

Gen I to V
Acid Armor increases the user's Defense by two stages.

Since Gen VI
Acid Armor's PP was changed from 40 to 20. If powered up by a Poisonium Z into Z-Acid Armor, all of the user's lowered stats are reset.