The Hippopotamoose is a neutral Mob exclusive to the Hamlet DLC. It resides in or around the Lily Pond biome, entering and exiting the water at its leisure. It remains neutral toward the player until attacked.
If one Hippopotamoose is attacked, nearby Hippopotamoose will become hostile and approach the player. They have a close range bite attack, as well as a long-range jumping slam attack which can knock down Trees and uproot Tall Grass and Saplings.
When moving through the water, they cause small Waves to appear, which can make the player wet and damage their Boat.