Espio and his teammates Vector and Charmy first made the acquaintance of Knuckles the Echidna when they teamed up with him, Mighty the Armadillo, and the robots Heavy and Bomb to oppose Dr. Eggman. At some point, they also interacted with Mighty's friend Ray the Flying Squirrel, though he and Mighty adventured apart from the detective trio. They were also one of four teams who joined forces to defend Mobius from the threat of Metal Overlord, alongside Team Sonic (which included Knuckles), Team Rose, and Team Dark. Unlike the other three groups, the Chaotix took on the monstrous robot having been hired to do so; their employer was eventually revealed to be a deposed Dr. Eggman. (VG: KC, SH, SU: #63)
Problems on Two Worlds
Espio and his teammates were later caught up in the Genesis Wave launched by Eggman and Dr. Wily, which altered both their worlds. At Sonic's request, they took up the search for the missing Knuckles, Tails, and Amy, only to lose Charmy as he went looking for ice cream. When the Bee inexplicably vanished, Espio noticed a mysterious figure trailing a purple scarf, and went after him while Vector took another route. Sadly, Espio's ninja training wasn't enough to save him from Copybot, who subdued the trio for delivery to Eggman and his new accomplice, Dr. Wily. Transformed into Espio Man of the Roboticized Masters, the ninja detective joined his teammates in battling Sonic, Tails, and their allies Mega Man and Rush. Espio Man lasted longer than his teammates Vector Man and Charmy Man, but was likewise restored to normal by Mega Man after being restrained by Sonic. Though somewhat embarrassed at having to be rescued, Espio was grateful to Mega Man, and joined his teammates in the search for Mega Man's missing brother Proto Man. (StH: #249, SU: #51, #52)
Espio and his teammates soon caught up with Proto Man, and eventually located the Wily Egg, which served as the doctors' base of operations. Despite their previous hacking experience, the trio of detectives were unable to crack the code of a teleporter pad located beneath the flying fortress. However, their location served as a gathering point for Sonic and Mega Man's allies from across the Skull Egg Zone. The group of heroes was then forced to deal with a new threat: a large force of Robot Masters dispatched by the doctors. Espio joined the battle, and eventually found himself facing off with a fellow ninja, Shadow Man. The battle soon led him to face off with Crystal Man, after which he and his teammates were cornered by the Robot Masters. Fighting on bravely, the Chameleon and his allies were soon joined by another band of heroes: the original line of Robot Masters from Light Labs. Bolstered by this group, the heroes continued to battle the Robot Master army until the Super Genesis Wave engulfed all of reality. Fortunately, Super Sonic and Super Mega Man were able to defeat the evil doctors, though Eggman managed to attack Super Sonic as he was attempting to restore Mobius to its previous state. (MM: #26, #27, SU: #53, #54, StH: #250, #251)
Helping Fix the World
Espio and his teammates were hired by Princess Sally shortly into the Shattered World Crisis to help hunt down the seven Chaos Emeralds, which were key to repairing the fractured planet. In the midst of their quest, they found Knuckles under attack by Dark Gaia's Minions in Pumpkin Hill Zone, and came to his aid. After learning that Knuckles was in the middle of his own quest, the Chaotix revealed their own, and the Guardian agreed to help them locate a Chaos Emerald in the region. They survived a harrowing trip through the air using their Sling Rings, only to run into a rival expedition: Nack the Weasel's Hooligans. The two teams fought briefly, but parted ways after learning that neither of them currently had the Emerald they were both seeking. Espio and the others made their way into Aquatic Mine, where they located the Chaos Emerald and Knuckles' quarry: the spirit Light Gaia. (SU: #63, #64)
At Vector's urging, Espio joined his fellow detectives in attempting to capture the spirit, but Knuckles stopped them in their tracks. After befriending the creature, whom Charmy named Chip, they were attacked by both the Hooligans and a Dark Gaia Titan. The Hooligans took advantage of the confusion to grab both spirit and Emerald, and left the Chaotix and Knuckles trapped with the Titan. Fortunately, they were able to take advantage of the mine's water redirection system to escape their near demise, and caught up with the Hooligans. While Bean the Dynamite was tricked into tangling with the Titan, Espio's teammates recovered and hid Chip and the Emerald, while Espio sabotaged the Hooligans' Emerald radar. Tricked into believing that Chip had escaped with the jewel, the criminals left, and Knuckles finished off the Titan. The Chaotix entrusted Knuckles with the recovered jewel, and left to search for others. Espio was later sent by Vector to Casino Park to investigate the Chaos Emerald Championship, and-despite losing some of his travel money-managed to enter Knuckles as a contestant after registering himself. (SU: #65, #66, StH: #268)
Espio took part in the first round against Bean the Dynamite, who quickly drove him out of his mind with his inane antics. To Espio's humiliation, Bean managed to get him so angry that he sent himself flying out of the ring, eliminating him from the tournament. This infuriated Vector, and Espio reluctantly joined Team Fighters in the audience. He and Sonic quickly agreed that Breezie must be rigging the tournament, as his last minute addition of Knuckles to the roster would have been obvious to her. Later, when the final round was interrupted by Metal Sonic, Espio joined the Freedom Fighters and Honey the Cat in thwarting the robot's attempt to steal the Emerald. (StH: #269, #270, #271)
Due to being a Chameleon, Espio is capable of blending into his environment and clinging to walls. He is also a trained ninja, and carries an array of ninja weapons such as throwing stars and kunai.
Espio is typically a no-nonsense personality, and usually the most professional of the Chaotix. While he apparently recognizes Vector as the leader of their group, he isn't afraid to argue with him. Espio also seems to have greater faith in mystical powers, such as Sling Rings, than his leader. In addition, he has great pride in his status as a ninja, as he was offended when Bean attempted a "ninja vanish" and when Bean called him a samurai, who he views as "lapdogs".
Espio is a purple chameleon with a yellow horn on his head. He wore green, black and yellow shoes with simple white gloves and had a ridge of teal/green scales down his spine and coiled tail.
In later years his skin became a brighter purple and his eyes are now gold. He now wears dark purple and black shoes with more elaborate cuffs and studded bands around the wrists and ankles. The scales on his back were reduced to three and are now black in color.