Gnarly Knuckles is an alternate version of Knuckles the Echidna from Sonic Prime, appearing in the Shatterverse. He is a tougher, more rugged interpretation of the character, shaped by a harsher reality. As with other Shatterverse variants, he helps show how different the characters can become across fractured worlds. Gnarly Knuckles contributes to the series as a memorable alternate counterpart rather than a main regular, emphasizing the show's multiverse concept and the many possible versions of familiar Sonic characters.