Knuckles the echidna is a supporting role in project chaos who lives a very different life than the other characters, he is apart of a echidna tribe that lives on protected land nearby green hills, knuckles is a stoic character that is not quite used to the world outside his tribe, he is eager to learn new things and often travels to green hills just to explore the town. Knuckles is close friends with Amy, the two met during the time sonic was away so knuckles has not interacted with sonic before the start of project chaos. He is a bit hesitant with befriending the blue hedgehog due to their clashing personalities, but trusts Amy that sonic is a good person.

The knuckles in project chaos is also very different to his game counterpart, though it mostly stems in his backstory. In terms of personality he is a no nonsense person who takes everything seriously. He struggles with being spontaneous and relies on routine, but with probing from the others he will join in on whatever sonic and Amy get themselves into.