Even without a brain - or even any form of bones for that matter - they are fascinating creatures. They emit a strange glow and can be seen even in the darkest depths of the Tibian seas, which also makes them a target for many of the larger inhabitants of the deep. Over time they developed a strong sense of danger and will flee as soon as anything other than their reflection approaches.
Jellyfish have 55 hitpoints. They are immune to earth and fire damage. On the other hand, they are weak against energy and physical damage. These creatures can neither be summoned nor convinced. In addition, they are able to sense invisible creatures.
Jellyfish yield 0 experience points. They rarely carry items with them.