From Halopedia, the Halo wiki
A zap-jelly is a predatory sea creature that populates the brackish seas of Balaho, the Unggoy homeworld. Zap-jellies glow with a faint pink light, which is noted to be similar to that of a Huragok. The translation "zap-jelly" may mean that this creature is similar to the Medusa cnidarians (jellyfish) that are indigenous to Earth.
List of appearances
- Halo: Contact Harvest (First mentioned)
- ^ Halo: Contact Harvest, page 186