Super Knuckles

Super Knuckles (スーパーナックルズ) is Knuckles' Super Form that is gained once all seven Chaos Emeralds are collected. The only appearances of Super Knuckles were in Sonic & Knuckles, Sonic 3 & Knuckles, and Knuckles in Sonic 2. Super Knuckles has a bright pink pulse to his body and a pink aura, but retains his basic physical form, unlike Super Sonic.Hyper Knuckles has after images behind him when he runs and he moves faster.

Abilities
While Super, Knuckles' strength is greatly enhanced, as well as his speed, jumping, gliding, climbing, etc. Like every other Sonic character, once he runs out of rings he loses his super form.

Trivia

 * Super Knuckles, unlike most other super forms, doesn't have a golden glow, but a pink one instead.
 * Super Knuckles was also referenced in Sonic Chronicles: The Dark Brotherhood in the Chaos Emeralds part of the journal, stating that Sonic, Shadow, Knuckles and a variety of people have been known to use the power of the 7 Emeralds to go up to powered up versions of themselves.

Archie Comics
In the Archie Comics, to set up a battle with Super Sonic, Knuckles' super form was dubbed 'Hyper Knuckles', to avoid the monotony of two supers against each other. In the comic in which Knuckles calls his super form 'hyper', he retains the pink coloring and experiences increased strength and speed.

Knuckles later obtains his Super form to fight Hunter on Angel Island using the power of the Master Emerald. In this form, Knuckles looks almost demonic and appears to be in pain when undergoing the transformation. As Super Knuckles, Knuckles was able to stop a "Chaos Spear" which sends its victims to the Egg Grapes and proceeded to attack Hunter, picking him up, spinning him around, and throwing him into the ocean where he drowned.

Screenshots
 File:Superknuckles2.png|Knuckles in Sonic 2 File:46968722.jpg|Sonic 3 & Knuckles File:Supknuxpower.jpg|Sonic 3 & Knuckles File:Sknuxwithspark.jpg|Sonic 3 & Knuckles File:Sknuxpower.jpg|Sonic 3 & Knuckles File:Hyperknuckles.gif|Sonic 3 & Knuckles File:HKnuxSlide.png|Sonic 3 & Knuckles 