Knuckles appears in Ultimate as an Assist Trophy. He attacks opponents with Homing Attack, and also digs into the ground and then uses an uppercut to attack. He may also simply punch opponents with his fists. He is also able to be KO'd.

As Knuckles does not exist within the base game of Super Smash Bros. Brawl, he does not play a role within the story. Knuckles is instead automatically unlocked after finishing the main story.

Tips and tricks to unlock characters fast in Super Smash Bros. Ultimate. Although there are purchasable characters, most characters can be unlocked in three different ways: Playing Classic Mode, fighting against a character in the game's adventure mode World of Light, or through the Rotating List.

For other uses, see Knuckles The Echidna. Knuckles is a playable newcomer in Super Smash Bros. for Nintendo Switch.