Knuckles was first introduced in Sonic the Hedgehog 3 on February 2 1994. Knuckles has since appeared in several Sega games, his most prominent game being Knuckles' Chaotix. Knuckles is tasked with protecting the powerful Master Emerald and the 7 Super Emeralds that keep his home, Angel Island, afloat. He is the last survivor of his clan, and has had little contact with anyone else but the animals that reside there. He is friendly but also quite naive and is quick to anger, a trait that Dr Eggman exploited to play Sonic against Knuckles while he stole the Master Emerald. They become good friends after this misunderstanding is resolved.
Knuckles has essentially the same abilities as other playable characters in Sonic games, but with a few unique abilities. Like other characters, he can run and, depending on which game you are playing, spin dash.
In later games, he has the ability to punch (and even combo) his enemies to defeat them. It is implied in early games that Knuckles has an intrinsic bond with the Master Emerald, and this is confirmed in Sonic Adventure, where he is able to track down the Master Emerald shards easily. Knuckles can also dig, which can be used in some games to find rings, extra lives, and power ups. In Sonic Adventure 2, Knuckles gains the ability to breath underwater indefinitely by finding an upgrade. Perhaps his most well known and widely repeated ability is his glide: by double jumping in nearly every game where he is playable Knuckles will perform a glide, gently falling until he hits the ground or a wall. He has the ability to climb up walls he latches onto with his glide.
Like Sonic, he is able to transform into a Super version that grants him increased speed and invulnerability if he collects all 7 Chaos Emeralds. Recovering the 7 Super Emeralds unlocks his Hyper Knuckles form, in which he is impervious to all damage except bottomless pits or getting crushed. He is also able to cause tremors that destroy all on-screen enemies when he latches onto a wall in this form.
From 1997 to 1999, Knuckles starred in his own ongoing comic book series fro m Archie Comics. The series, a spin-off of Archie's "Sonic the Hedgehog" series, ran for 32 issues.
The series followed Knuckles and his friends The Chaotix as they protect Angel Island (then just called "The Floating Island") and unraveled it's many mysteries. It featured many concepts original to the series, adding many new concepts to Knuckles expanded universe. Many of these concepts, like the "Dark Legion", a villainous group of echidnas banished to a prison-like "Twilight Zone", were seemingly used as inspiration for Bioware's Sonic Chronicles: The Dark Brotherhood.
The series was written by veteran Sonic comic writer Ken Penders, and drawn for most of the first 25 issues by artist Manny Galan.
- According to the Sonic comic series, Knuckles can play the guitar.
- Judging by Sonic Adventure 2's soundtrack Knuckles is an accomplished rapper whose claim to fame is rapping about the places he visits during his adventures (such as Pumpkin Hill and Meteor Herd) and the burdens of being the protector of the emeralds.
- Knuckles' first appearance was in Sonic 3, but he wasn't made playable until Sonic and Knuckles. After it was released, Sega revealed that by inserting Sonic the Hedgehog 3 into Sonic and Knuckles, the player could unlock the ability to play as Knuckles, which was the only way certain areas could be reached.
- There are varying reports of Knuckles' lineage, but it is generally agreed upon that the echindas were an ancient clan sworn to protect the Master Emerald, and Knuckles is a descendant of that clan. It is rumored that Tikal, from Sonic Adventure, may be of some relation to Knuckles.