FusionDex

Wailfing drifts around on the surface of the ocean, poisoning the water around it. Occasionally, it becomes so bloated with toxic gas that it floats up into the air and may be blown onto land by the wind.

Getting up close to a Wailfing will give you a chance to observe, through its thin skin, the toxic gases swirling inside. While this Pokémon usually lives in the sea, it can survive on land, although not too long.