Dmitri Smerdyakov was the illegitimate son of the patriarch of the Russian Kravinoff family and a servant. His only friend growing up was Joe Cord, an American boy who once saved his life while his half-brother Sergei, the legitimate heir, and his father treated him with contempt and brutality. This scarred Dmitri so deeply that he repressed his very identity and came to believe he had been friends with Sergei instead. His loss of self led him to become a master of disguise and a Soviet spy. Initially without super-powers, the Chameleon relied on his skills and a mixture of costumes and make-up to conceal his identity. He wore a multi-pocket disguise vest in which he kept the materials he would need to mask himself at short notice.
In his first known appearance, Chameleon impersonated Professor Newton, a government scientist, to steal half of some missile defense plans. He then sent a message to Spider-Man, electronically contacting him via his spider-sense, requesting a meeting and implying a profitable venture. Chameleon disguised himself as Spider-Man, though, and stole the second half of the plans, making his escape just as the real wall-crawler showed up. Spidey was at first framed for the theft but managed to bring Chameleon back to the police. Chameleon disguised himself as a police officer, scaring Spider-Man off by having the other police attack him. Spidey left the scene, thinking he had failed, not realizing that he had torn Chameleon's police uniform, allowing the cops to see the phony Spider-Man outfit underneath.
Chameleon was deported back to Russia, but returned soon after, having given up being a spy, and turned instead to a life of crime. Stymied again by the wall-crawler, Chameleon invited his half-brother, now known as Kraven the Hunter, to America to capture Spider-Man. The duo worked together, with Chameleon even dressing as Kraven to fool Spidey. Ultimately, though, both were defeated and deported by freighter where they bribed a sailor to set them loose in a lifeboat near Long Island. They came ashore right by Tony Stark�s munitions factory and Kraven was quickly captured by Iron Man. Chameleon concealed his presence but decided to prove his superiority over Kraven by defeating the armored Avenger. Disguising himself as Captain America, Chameleon contacted Iron Man and convinced him that he was the real Captain America and that the Captain America at Avengers Mansion was really Chameleon. Iron Man and Captain America fought it out until Giant-Man captured Chameleon and revealed the truth.
Chameleon quickly escaped prison and went to work for the Leader as his top lieutenant. The Leader sent him to New Mexico to learn the secrets of the Hulk. There, Chameleon impersonated General Thaddeus "Thunderbolt" Ross and Dr. Bruce Banner, stole a grenade-size gamma bomb and took Betty Ross as a hostage. Realizing he couldn't escape, Chameleon set off the bomb, which was smothered by the Hulk, dampening the blast. Though caught in the rubble, Chameleon survived and escaped, remaining in the Leader's employ until his boss' supposed death.
Chameleon next encountered Spider-Man after taking the place of Captain George Stacy who had been hired to protect a valuable art exhibit at the Midtown Museum. Peter Parker and Stacy�s daughter Gwen were there and noticed that the Captain didn't seem to recognize them. After the exhibit was stolen and Stacy found drugged back at his apartment, Peter realized the Chameleon must have been involved. He persuaded Joe Robertson to plant a story in the Daily Bugle about a transfer of bonds and trapped Chameleon trying to steal them. Chameleon tried to escape through disguise but made the mistake of impersonating the one person Spider-Man knew to be a fake: Peter Parker. The terrorist organization Hydra arranged for Chameleon's escape from prison so that he could impersonate Dr. Henry Pym and steal Pym's research combating their biological weapon Virus Nine. Pym, as Ant-Man, teamed with the Hulk and thwarted Chameleon, though it appeared at the time that Chameleon had murdered Bruce Banner. Later, Chameleon impersonated Spider-Man, attempting to free his friend Joe Cord from the New York Men's Detention Center. Accidentally striking the Hulk with his car, Chameleon quickly disguised himself as Hulk's friend Rick Jones and convinced the green goliath to break Joe out of jail. However, in a battle with police, Joe protected Chameleon from gunfire and was killed.
Designing a new costume that could instantly duplicate any clothing, Chameleon went back to crime. He was pursued after a jewel heist by Torpedo (Brock Jones) and Daredevil. His quick-changes failed to help him since Daredevil tracked him by his heartbeat. His next costume innovation used a holographic belt that stored the appearances of people he came into contact with and allowed him to take on their look. In one encounter, he managed to convince people that Spidey had attacked an old lady, leaving the wall-crawler's newly restored reputation in tatters. Later he obtained further powers by using a serum that could let him change his appearance at will. This liquid actually allowed his skin to be flexible enough to shift its appearance into any disguise Chameleon desired. He tried to kidnap a top scientist but was again thwarted by Spider-Man.
Chameleon then set his sights on ruling the New York underworld. He kidnapped J. Jonah Jameson, impersonating him in a long-term bid to influence events through the Bugle, and formed an alliance with Hammerhead. The Kingpin of Crime was embroiled in a power struggle with the werewolf Lobo Brothers Carlos and Eduardo. Chameleon and Hammerhead tried to instigate a full-on gang war, from which they would pick up the pieces. Chameleon, posing as Jameson, injected Spider-Man with a potion that left him unconscious for several days. Recovering, Spider-Man went after Jameson and discovered he was the Chameleon all along. Hammerhead and Chameleon's plans continued as they ambushed the Lobo Brothers and Kingpin during peace talks. After carving up the city into territories they each agreed to control, their alliance collapsed and their influence waned.
Soon after, Chameleon took the guise of Doctor Turner and persuaded Spider-Man to subject himself to a machine that supposedly would analyze his spider-powers. The machine, designed by the Tinkerer, ended up temporarily removing the wall-crawler's abilities instead. After discussing it with Mary Jane, Spider-Man decided to have his powers removed permanently. Now powerless, Spidey was attacked by Tarantula (Luis Alvarez) and Scorpion and needed the Black Cat's help to survive. Changing his mind, Spider-Man searched for Doctor Turner, eventually realizing he was actually Chameleon, by which time his powers returned naturally. The Chameleon's next big plan was set up by the Green Goblin (Harry Osborn) before his death. The Goblin persuaded Chameleon to create two robots that would appear to be Peter Parker's dead parents in an effort to get Peter to tell them who Spider-Man really was. The Goblin already knew Spidey's identity but wanted to mess with Peter's head so he convinced Chameleon that Parker, due to all the photos he had taken, was sure to know Spidey's identity. When Spider-Man discovered the fraud, he went crazy with rage and disappointment at losing his parents again. The Chameleon escaped to Kraven's old mansion while Spider-Man hunted him down. Faced with a more fearsome and vicious Spider-Man than ever before, Chameleon's repressed memories of his unhappy childhood with Sergei returned and he fell into a coma-like state.
The Chameleon was taken to Ravencroft Institute but escaped after assuming the identity of his doctor, Ashley Kafka. He kidnapped Spider-Man and unmasked him, finally understanding why Spider-Man had been so mad after discovering the robot parents. Chameleon imprisoned Peter and convinced him he was a writer named Herbert Smith who was incarcerated in an insane asylum. Chameleon then took on the role of Peter himself but was foiled by Mary Jane, armed with a baseball bat, who knew her husband too well to fall for the impersonation. Escaping, he was shot by his nephew Alyosha Kravinoff, who said there could only be one Kravinoff in the world. Chameleon again barely survived. Later, he arranged to meet Spider-Man on top of the Brooklyn Bridge, wanting to make up for his crimes. There, he tried to commit suicide by jumping. Spider-Man blamed himself for this apparent death but Chameleon somehow survived. He was later recommitted to Ravencroft. In Chameleon�s twisted mind he now believes himself to be his half-brother, Kraven the Hunter. This didn�t stop him from joining Norman Osborn�s Sinister Twelve, however.