Equipped with hundreds of tiny mouths, a single giant Normura jellyfish will gorge on zooplankton in the ocean, increasing their body weight up to 10 percent every day. Scientists theorize warming ocean temperatures could be raising the rate of the jellyfish's reproduction, and causing the "blooms." Each jellyfish carries over one billion eggs. "Monster Jellyfish" premieres on Thursday, May 19 on NatGeo WILD. (Jesse Stern/National Geographic)