Blue Jellyfish

Blue Jellyfish are one of the new mobs in Terraria that were added during the 1.0.5 update They can be found in any pockets of water, except for oceans, where their other family member spawns, the Pink Jellyfish. They have a blue tinge, and release light from their bodies. They drop glowsticks on death, making them a source of light if you are ever in a cave with no wood or torches, an Orb of Light, or a Mining Helmet. They have 30 health.