Ethereal beings usually found near places of rest, acting as protectors. They are usually peaceful, but if angered, they attack with deadly poison fired from a distance.

Spirit Jellyfish are blue in color unless provoked, after which they will turn red and start attacking. Blue Jellyfishes are safe to approach. Their ranged jet attack causes Poison buildup. Once hostile (turned red) they will attack the player on sight, and will make other Spirit Jellyfish aggressive as well. In a few places, such as northeast of Castle MorneDungeon and southwest of the Four Belfries, there is a small group of Spirit Jellyfish that spawn red and are always aggro. Particularly weak to Lightning damage. Resists Strike damage.