Knuxerci

Knuxerci is the het ship between Knuckles and Perci from the Sonic the Hedgehog fandom.

Sonic Boom (TV series)
In "Battle of the Boy Bands", Perci was one of the brainwashed Justin Beaver fangirls obsessed with his mind control music. She attended a Justin Beaver concert in which Knuckles' band, Dreamboat Express, challenged him to a sing-off. Perci and the other fangirls were freed from the mind control after Sonic used a counter-frequency on Justin, then cheered on Knuckles' band under a new name, Dude-itude.

In "Late Night Wars", Knuckles began his moments of fame when he was attracted to photo shoots after wearing a battered trashcan as a hat. Later, he was seen walking past Meh Burger with Perci and her twin sister Staci. When Soar pointed a microphone at him, he aggressively blocked the reporter's camera in front of the twins.

In "Fire in a Crowded Workshop", Tails went inside his smoking workshop and saw Knuckles, Sonic, Amy, and Perci covered in soot. Sonic explained his own story of how the workshop caught fire, but Knuckles disagreed with this. Knuckles then told his own exaggerated version: after meeting Perci, Sonic made a fool of himself and Knuckles humbly introduced himself to her. In reaction, Perci admired her "muscles and brain-smartness". Knuckles then accompanied her to Tails' workshop. While Sonic hurt his finger as he was repairing Perci's bicycle, Knuckles washed Perci's scarf and placed it in a kiln. He offered her a pillow but Amy snatched it, asserting her role as a medic. Sonic and Amy fought over the pillow, then suddenly the workshop catches on fire. Knuckles uses his ice-breath to extinguish the fire, to the affection of Perci. He blameed Amy for starting the fire by tossing the activated heating pad on the newspapers, but Amy disagreed with his version of the story and told them her own version. Aggravated by the contradicting points of view, Perci told her own version of the story that Sonic, Knuckles, and Amy were equally fretting over the accident. Tails revealed to them that accident was caused by his new security system that should have gone off. Resolved, Knuckles, Sonic, and Amy went out to get some food.

In "Three Men And My Baby!", Perci, Staci, and Zooey glanced at the passing Knuckles, Sonic, and Tails who are feeding Lady Walrus's younger son Chumley.

Fanon
There are a handful of fan art of this ship alongside screenshots from "Fire in a Crowded Workshop" on DeviantArt.

Perci has a very small following on AO3.

Fandom
DEVIANTART
 * Knuckles and Perci on DeviantArt
 * Knuckles X Perci on DeviantArt