Fuels Robot Jellyfish Hydrogen Fuels Robot Jellyfish Published by Lifeisbeautifull June 10, 2012, Category: Technology Hydrogen fuels robot jellyfish. Medusa Jellyfish are the major non- polyp form of individuals of the phylum Cnidaria . They are typified as free-swimming marine animals consisting of a gelatinous umbrella -shaped bell and trailing tentacles.