Klaus Voorhees was a citizen of the Netherlands whom turned into Cobra when he let a cobra bite him to get away with a murder, afterwards consuming an experimental antidote. Unknown to him however the snake was irradiated in an experiment, and as a result he gained cobra like powers.
King Cobra was created by Stan Lee and Jack Kirby and first appeared in Jouerney into Mystery Volume 1 issue 98 (1963).
Major Story Arcs
A career as a criminal
Soon after deciding to start a criminal career, he was stopped by Thor. He then forged an alliance with Mr. Hyde, that continued for a very long time. They faced enemies like Daredevil and Spider-Man. Cobra also joined the Serpent Squad, they helped an Atlantean warlord known as Krang, but Cobra felt out of his element. Soon he again teamed with Mr. Hyde, but this time the partnership didn't last long. Cobra left Hyde behind when escaping Rikers Island. Later, Hyde was hunting him and he feared for his life, with the help of Spider-Man he was able to escape Hyde's wrath.
King Cobra again teamed with others like him, this time it was called the Serpent Society. After several betrayals, Cobra was left the leader of this group. Now feeling like a new man, he decided to face his greatest fear, Mr. Hyde. He fought him face-to-face. After defeating him, he renamed himself King Cobra. He tried to get some order into this group, but it backfired and the group fell apart. King Cobra soon was arrested, and sent to the Vault. When the breakout happened he was among the escapees. A new hero Toxin tracked him down with the help of Mr. Hyde.
Civil War and Thunderbolts
When the Superhuman Registration Act went through, King Cobra joined the Thunderbolts.
Sano Orii currently employs a super-powered mercenary named Cobra who is not Klaus Voorhees.
The Cobra possesses certain unusual physical powers derived from his mutagenically altered physiology which among other things help him simulate the movement of a snake. All of the bones in his body, including his skull, are malleable and his muscle tissue is exceedingly resilient, making his body very flexible and pliant. It is nearly impossible for him to break a bone or tear a muscle. Hence, the Cobra can survive impacts that would kill or inflict major injury upon a normal human being with little or no injury to himself.
The Cobra's flexibility enables him to slither into and out of very tight and small places. Through compressing his body, the Cobra can fit into any hole or slot down to four inches in diameter. By using his flexibility to wrap himself about a victim's body and then exerting his full strength, the Cobra traps that victim within his "Cobra Grip." No normal human being can break free of his grip unless he is extraordinarily well trained in fighting, and even many superhumanly strong beings would have difficulty freeing themselves.
Cobra would be involved in a story taking place in the Marvel Adventures comics which are standalone stories and does not take place in the current Marvel Universe continuity.
Cobra and the Serpent Society would kidnap Dr. Curt Connors when they learn the truth about his Lizard formula and forced him to experiment on innocent civilians. The Serpent Society had Dr. Connors modify his formula and had plans to contaminate the water supply in New York so everyone would transform into humanoid lizards. However their plans were thwarted by Spider Man so Cobra and the rest of the Serpent Society retreated when Connors ingested his own formula and transformed into a giant, monstrous Lizard.
Powers and Abilities
Strength: able to lift own body weight, speed peak range - 700 MPH, Enhanced Durability. Short range energy projection, short duration, single energy type.
Avengers: Earth's Mightiest Heroes
Cobra first appears in the episode, "Breakout, Part 1" as one of the escaped criminals from the Big House. He later appears with the rest of the Serpent Society in the episode "Ultron-5." Unlike his comic book counterpart, Cobra has the ability to turn his legs into a snake-like tail, wrapping it around his enemies and constricting.