Wailmer is a spherical whale Pokémon with no tail. It has a dark blue topside and a tan underbelly with grooves. It has two fins that have finger-like appendages, baleen plates that resemble teeth, and a blowhole on the top of its head. Wailmer stores water inside its body, which it expels through its nostrils to startle people. When storing water in its body, it can turn into a bouncing ball. The more water filling its body, the higher it can bounce. It becomes lethargic when it is dry. It eats tons of food a day. It lives in the sea, and can only live on land for a short amount of time. It occasionally bounces onto the beaches to play.