Inter-Dimensional Whale

Inter-Dimensional Whale (次元の勇魚) is the boss of the Fourth Wave from the Cal Mira wave.

Overview
The Inter-Dimensional Whale is estimated to be over 150 meters long. It is described as looking like a pale white Sperm Whale, with a long twisting horn on its head similar to a drill. Its body is also covered in jewel-like bumps which could all independently launch magic spells, including heat beam attacks.

The whale was killed by L'Arc very quickly. After the wave, the beast's corpse was beached and cut up so it's parts could be sold off and be given to the heroes.