Jelzap are one of the few natural aquatic predators on the planet Tallon IV. A fish-like species, it is composed of two halves of heavily armored skeletal structure connected by a link of electrical impulses. The upper half houses the brain while the lower half houses the digestive organs. These two halves work well enough in conjunction to make it the apex predator of Tallon's waters. The electromagnetic field it emits is known to briefly disable any sapient's electronic visor that comes too close to it.
When approached by sapients, one should recognize that the Jelzap is essentially immune to conventional weaponry at first, due to their heavy armor. Only when they open their mouths to suck in prey with their electromagnetical field do they reveal their vulnerable core. At this time, a foe must tread carefully as they can be pulled off of "platforms" that they may be standing upon.
- Metroid Prime (First appearance)