Maulruses are burly anthropomorphic walruses with golden tusks whose bodies are covered in a thick purple hide. In an unused sprite for the NES version, it originally had a grey hide with white tusks. The pinnipeds can only be encountered at sea and their bulk allows them to slowly recover from their injuries in battle. In spinoff games, the Maulrus has gained an affinity with ice attacks.
Maulrus appears as an A-rank monster of the Nature family on a banner alongside Gracos as part of the 1-Year Wrap Party post-anniversary event. It can participate in the King kelp's Battle Road as a party member.
The Maulrus has the distinction of only appearing in remake versions of Dragon Quest IV. Although it has a sprite and stats in the original Famicom version of the game, it cannot be encountered anywhere. It shares this in common with four other monsters that can be encountered at sea: Axolotl, Glugworm, Mangler fish, and Terroranodon.