Espio the Chameleon is an anthropomorphic chameleon who is an expert ninja. He is described as the "guardian of honor" of the Chaotix, also being the calmest. He has a "militaristic discipline" while also being quiet and laid back. Confident in his skills, opinionated and self-obsessed, he revels in training and self discipline. He is not concerned by danger, and often yearns to face it in order to use his ninja skills. With his extensive training in ninjutsu and an ability to turn himself invisible, he is able to move around unnoticed. However, a blunder like a sneeze could cause him to inadvertently become visible.
Espio was created by Sonic Team for the video game Knuckles' Chaotix, as part of the newly introduced Chaotix team of private investigators. In the game, his color subtly changes while he moves to demonstrate the technical capabilities of the Sega 32X console.Espio was incorporated into Sonic Heroes as part of a move to reintroduce neglected characters, and because the development team considered him to have a unique, interesting personality. He was the designated "speed" character in Sonic Heroes while teammates Vector the Crocodile and Charmy Bee respectively represented "power" and "flight". Espio was added to Sonic Rivals 2 to help "round out our cast of characters", and because designer Takashi Iizuka appreciated the character's "stealthy agility".
