Louies, or Rooi (ルーイ), are kangaroo-esque animals that Bomberman can ride around on. Each different colored Louie has his/her own unique ability, similar to the power ups in the game. Another benefit of riding a Louie is that if a blast or hazard hits you, the Louie will take the damage and be destroyed, making them act as a Heart item as well.
Louies were first introduced in Bomberman '94. They have appeared in many games ever since, but sometimes are replaced by other ridable creatures like Tirras.