Or tail-oil-loss.

Generation III Hoenn

054 Kanto

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Ruby Azurill spins its tail as if it were a lasso, then hurls it far. The momentum of the throw sends its body flying, too. Using this unique action, one of these Pokémon managed to hurl itself a record 33 feet.
Sapphire Azurill's tail is large and bouncy. It is packed full of the nutrients this Pokémon needs to grow. Azurill can be seen bouncing and playing on its big, rubbery tail.
Emerald Its tail, which is packed with nutrition, is very bouncy like a rubber ball. On sunny days they gather at the edge of water and splash about for fun.
FireRed It battles by flinging around its tail, which is bigger than its body. The tail is a floatation device in water.