The Battiling Blowfish first appears at the end of Prospecter's Trench on Planet Aquatis, where it's pilot is surprised by how the player managed to get that far, but than decides to attack the player with the Battiling Blowfish. In this phase, the Battiling Blowfish will fire a large beam at the player, to damage it, the player must attack the tailfins at the back of it. When the Battiling Blowfish is defeated, it will explode and transform into it's second form.