Heartless that attuned to the darkness in Clayton's heart. It somehow manipulated the light to turn invisible and fought alongside Clayton.
In Kingdom Hearts, the Stealth Sneak was attracted to the darkness in Clayton's heart, and used him as a puppet to help it defeat Sora, Donald, Goofy, and Tarzan. However, the heroes prevailed, resulting in the death of both Stealth Sneak and Clayton, as it toppled on to him and crushed him to death.
The Stealth Sneak is a bipedal lizard resembling a chameleon. It has a yellow body, with five short spikes along its back. It often stands hunched over, holding its arms out in front of it. Its entire upper body is covered in stripes of various shades of green and yellow, reminiscent of camouflage clothing. Its hands and feet have four toes each, two in front and two in back, with black claws.
Its prehensile tail is curled up behind it in a spiral. It has a mouth lined by short, pointed teeth, a pink tongue that can extend to surprising lengths, and large yellow and orange eyes with small black pupils. It also has a large, yellow horn on the tip of its snout. Its Heartless emblem is on its chest. The standard Stealth Sneak bears a strong resemblance to a chameleon that Simba roared at in The Lion King just before the wildebeest stampede.
In Kingdom Hearts Final Mix, the Stealth Sneak's upper body becomes completely light green and is covered in intricate, black markings. The only other noticeable changes are that its horn becomes white and its underbody becomes tan.
Both halves of the Stealth Sneak's name reference its ability to become invisible. "Stealth" means "acting in secrecy", while "sneak" means "to hide".
- There seems to be some confusion on how the Stealth Sneak killed Clayton. When the Disney villains are discussing it, Oogie says he "got chomped", and indeed, if one looks closely, it does appear Clayton got crushed in the Sneak's open jaws as it fell on top of him. The cutscene is not clear enough to make out all the details though. However, it is evident that Clayton lost his heart to darkness, as he disappeared with the Stealth Sneak after being defeated.