Hydro-Vipers are qualified EELS (Cobra Frogmen) who volunteer to be surgically altered to withstand nitrogen narcosis and other side effects of deep diving. Synthetic webs are implanted between their fingers and subcutaneous fat production is stimulated by chemical injections to provide natural insulation. The long term effects of these procedures is known to be psychologically destabilizing...
"I'm sorry, those guys just aren't human anymore. They have a handshake like a dead mackerel and they leave damp spots on all the furniture. I realize that they are virtually unbeatable in underwater combat, but so is a great white shark-and I'll bet the shark is friendlier!"
Hydro-Viper is a Cobra operative in the original G.I. Joe: A Real American Hero line. First released as a Hasbro carded action figure in 1988, with 1 distinct figure version produced across the 1982 to 1994 ARAH run.
Hydro-Viper did not appear by name in the Sunbow or DiC cartoon series synopses. Original Hasbro file-card lore and Marvel ARAH comics appearances are the primary characterization sources.