Some time ago, Knuckles participated in a situation involving the Space Colony ARK in which Eggman used its Eclipse Cannon to blow up a part of the moon in order to show the world the power that he wielded. These events lead to Knuckles, Sonic the Hedgehog, and Miles "Tails" Prower teaming up with Rouge the Bat, Shadow the Hedgehog, and Eggman in order to fight a bigger threat. (StH: #5, #6)
Later, Knuckles, Sonic and Tails formed a team. Soon after, a battle happened between Team Sonic and Neo Metal Sonic - the powered up form of Metal Sonic - who was impersonating Eggman. This time, the fake Eggman was piloting the Egg Emperor mech, but Knuckles and his friends defeated the mech. After learning that Neo Metal Sonic had taken over the Eggman Empire however, Knuckles and his team defeated the robot, causing him to revert back to normal. (StH: #1, #7)
In the recent past, after Sonic got captured by Dr. Eggman, who was able to seize control over most of the world in doing so, Knuckles became the commander of a resistance group that opposed Eggman's reign (although it was Amy Rose who kept the group organized). Later on, after being reunited with Sonic, he, alongside the rest of the Resistance, defeated Dr. Eggman, thus ending the Eggman Empire's reign over the world.  This ended in a confrontation between Sonic and Eggman, the latter piloting his latest Death Egg Robot. (StH: #1)
After the war, Knuckles and the Resistance set out to clean up from the war. However, with the Eggman Empire's Badniks being everywhere and randomly attacking anyone they came across, Knuckles and the Resistance had to work from a centralized, organized position that would allow them to combat the Badniks more effectively. (StH: #2)
Eventually, Knuckles went to investigate a town, but did not report back after a while. While there, he single-handedly destroyed the Badnik horde that was surrounding said town. After finishing off a Death Egg Robot sentinel, Sonic came by on Amy's request to check up on him. Knuckles explained that the town's Wispon shipments had dwindled and that he came by to find out why. He and Sonic entered the town, finding the citizens in a panic. There, they were informed by the gatekeeper that their town's Wispons had been stolen by a duo of mercenaries that had, before the war ended, driven Eggman's forces away and saved the town, only to then conquer the town and keep its arsenal to themselves. Knuckles and Sonic went off to the town's supply depot-turned-fortress to put an end to the mercenaries' cruelty. There they had found several Wisps being horded. Soon, Knuckles and Sonic confronted the mercenaries, who introduced themselves as Rough the Skunk and Tumble the Skunk. A battle ensued between the four that seemed to be evenly matched, until Sonic called upon the help of the Wisps who remained in the horded Wispons. After the Wisps broke out of the Wispons, Knuckles and Sonic easily defeated the mercenaries. Rough and Tumble were then taken to the town's jail while Knuckles and Sonic celebrated their victory with the villagers and Wisps. (StH: #2, #3)
The Battle for Angel Island
Meeting with Sonic, Tails and Amy in Resistance HQ, Knuckles learned from Sonic that Neo Metal Sonic was the ringleader behind the recent organized Badnik attacks. As it turned out, the robot had taken over as head of the Eggman Empire and was currently trying to conquer the world for Dr. Eggman with an unknown plan. In an effort to undermine Neo Metal Sonic's scheme, Knuckles and Amy decided to help Sonic and Tails search for any old plans that could tell them what Neo Metal Sonic was up to. (StH: #7)
Continuing his work from Resistance HQ with Amy, Knuckles eventually sensed that the Master Emerald was calling out to him. Immediately after, Knuckles and Amy were contacted by Sonic and Silver the Hedgehog, who, after having discovered Neo Metal Sonic's plan, told them to call in everyone. (StH: #8)
After having called their allies to Resistance HQ, it was revealed to the assembled heroes that Neo Metal Sonic had taken over Angel Island and turned it into a flying fortress. To make matters worse, Neo Metal Sonic had also secured the Master Emerald for himself on the island. Outraged at what had been done to his homeland in his absence, an upset Knuckles blamed himself for this. Knuckles was thus eager to volunteer for the team that would confront Neo Metal Sonic and secure the Master Emerald. Also, when Tails tried to discourage Blaze the Cat from going after Neo Metal Sonic as Burning Blaze, Knuckles told him that the Master Emerald could not interfere with the Sol Emeralds (the source of Burning Blaze's power). In the end, Knuckles and Sonic were chosen to confront Neo Metal Sonic and secure the Master Emerald while the others focused on breaking the Egg Fleet's control over the island. (StH: #9)
On the way to Angel Island, Knuckles refused to relax while his home needed him. When they finally neared Angel Island however, the Egg Fleet began bombarding their ship. Using their Extreme Gears, Knuckles and Sonic left the crashing ship and flew to the Master Emerald's shrine, which had been turned into a fortification. Inside it, the two heroes found Neo Metal Sonic on top of the Master Emerald. When they tried to confront him however, Neo Metal Sonic used the Master Emerald to turn into Super Neo Metal Sonic. (StH: #9)
Knuckles is an anthropomorphic echidna with red fur that covers most of his body, peach skin on his muzzle, a white crescent-shaped patch of fur on his chest, and purple eyes. He also has seven dreadlock-like spines on his head and a medium-sized tail.
For attire, Knuckles wears red and yellow shoes, each with green cuffs and a grey, sextuple-bolted plate on top. He also wears white, mitten-like gloves with sock-like cuffs and two spiked knuckles on each hand. Both his gloves are quite large.
Knuckles is a tough, wild, egotistical, and headstrong echidna. Serious and stubborn, Knuckles has no patience for stationary work, like paperwork, and prefers to be where the action is. However, he is an overall nice guy in normal conversations.
Knuckles is fiercely loyal to his homeland and prefers to stay there. As such, when anything bad befalls the island and its Master Emerald, Knuckles takes it very personally and blames himself for not being able to prevent it. He will also not rest or take it easy until he is sure that his island and its treasure are safe once more. Despite his ties to his home however, Knuckles is very heroic and is willing to leave his duty whenever his help is needed. When not performing his duties, Knuckles prefers spending his time going treasure hunting.
Knuckles is somewhat gruff and has an equally short temper. Combined with his heroic morals, he is quick to anger when witnessing villains' despicable behavior. However, he is not the sharpest tool in the shed and will willingly jump into a fight without thinking once about the consequences. Regardless, he is very strong-willed and will not give up on his goals once he has set them.
Knuckles possesses incredible strength, being as strong as Sonic is fast; with a single punch, he is able to pierce thick metal with ease. By stretching his arms and legs outwards while airborne, Knuckles can catch the air under his dreadlocks to ride on air, allowing him to glide through mid-air. Also, by using the spikes on his fists, Knuckles can scale any kind of surface with ease. He is also a great hand-to-hand combatant.
Being the guardian of the Master Emerald, Knuckles possesses a special link to the massive gem. As such, he can sense the Master Emerald's energies and will.
Sonic the Hedgehog
Sonic is both a close friend and rival to Knuckles, with the two of them being no stranger to butting heads over a disagreement at worst, or partaking in banter with each other at best. Despite this, the two put a lot of trust in one another's abilities and work near perfectly to get the job done.
- Blaze the Cat
- Shadow the Hedgehog
- Silver the Hedgehog
- Sonic the Hedgehog (best friend and rival)
- Rouge the Bat
- Blaze the Cat
- Tangle the Lemur
- Whisper the Wolf
- Eggman Empire
- Rough the Skunk
- Tumble the Skunk
- Head writer Ian Flynn has revealed on Twitter that Knuckles's measurements are the same as those of his game counterpart.
- Knuckles made his video game debut in the 1994 Genesis game Sonic the Hedgehog 3 as a non-playable character, before finally becoming one later that year with the release of the game’s direct follow-up Sonic & Knuckles.
- Incidentally, Knuckles made his IDW debut in the third issue.