The amphibian like creatures which were dubbed as the Hydro-Men were created by Dr. Herman Frayne who went by the alias Dr. Hydro. He was an ecologist who believed that mans only salvation is to adapt and live in the sea. The followers of Dr. Hydro built an artificial island off the Atlantic coast, and used a chemical mist, the Terrigen Mists possibly acquired from Maelstrom and or Phaeder, which mutated them into green skinned scaly amphibians. 
Dr. Hydro also used the chemical to hijack five airliners and expose the passengers as well. Namor the Sub-Mariner came to the rescue of the humans and defeated the cult. Namor was unable to restore the humans to normal, so he requested help from Reed Richards aka Mr. Fantastic. Dr. Richard discovered through studying the green mist, that it has the same properties of the Terrigen Mists used by the Inhumans in their Rites of Passage. Dr. Richards with this knowledge was then able to cure all the converted humans using an Anti-Terrigenesis Compound.
- 5 Hydro-Men (Earth-616) Members
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