Knecapeon "Kneecaps" Mace was the son of Lara-Le and Wynmacher and half-brother to Knuckles the Echidna. A rather energetic infant, he is extremely attached to his parents and fond of his brother Knuckles, whom he enjoys hitting on the head with a rattle. He was born some time during Knuckles' powerless year in Knothole, his conception having been revealed to Knuckles some time before his temporary death. Kneecaps remained with his parents as they stayed with the Dark Legion as the Angel Island resistance to Dr. Eggman's regime, then in the village built by the survivors of Echidnaopolis, followed by his transportation to the ruins of Albion. Subsequently, he would join the majority of Mobius' Echidnas in exile courtesy of Thrash the Devil.
Knuckles first learned of his younger brother's conception from his mother Lara-Le after the Echidnas were brought back from the Twilight Zone thanks to the powers of Chaos Knuckles. Lara revealed it during a heated argument with Knuckles over his support of Dimitri, in which she decried Dimitri as a dangerous threat to her children, which briefly had Knuckles confused as he was an only child at the time. Due to his temporary death and then being cut off from Angel Island for a year, Knuckles was absent when Kneecaps was born and never received word of it from his parents. (StH: #108)
Kneecaps first met his older brother when Knuckles returned to the island with the Chaotix and Sonic the Hedgehog to rescue Locke from the Dingoes. Kneecaps took to his older brother immediately, hitting him with his rattle and otherwise playing with his older sibling. Weighed down by the knowledge that his people—including Wynmacher—believed him to be the Avatar foretold by the Ancient Walkers, by his weakness upon exposure to the Master Emerald, and by all that had befallen his home and people in his absence, Knuckles was unable to reciprocate his younger brother's affection, much to Kneecaps' dismay. (StH: #138, #139)
Kneecaps and his parents lived for a time amongst the Dark Legion, but relocated to a small village with other survivors of Echidnaopolis following the beginning of the civil war between the Flame Legion and Frost Legion. Later, Kneecaps was among the many sent by the second Enerjak—a brainwashed Knuckles determined to protect his people—to the original Echidna city of Albion, which had been leveled by Dr. Eggman. Kneecaps remained innocent through this traumatic period, and once caught a glimpse of Knuckles as his older brother flew overhead, wracked with guilt due to his role as Enerjak. While playing with his parents, he notices Knuckles, points his rattle to him and calls him Na-Na. When Knuckles leaves, he said good bye to his brother innocently. Kneecaps continued his young life peacefully, until he and his parents were sent by Thrash the Devil through a warp ring to an unknown location. (StH: #139, #171, #181, #186, #244)
As a baby, Kneecaps doesn't have a very developed personality. He is very energetic and positive, particularly if either of his parents or Knuckles is around. Because of his affection for his family, he can get very depressed when one of them is sad or not reacting to him. He is also terrified by massive displays of power, as seen when he saw Super Knuckles power up and when he saw Enerjak appear in the Echidna village on Angel Island.
Because of his youth, he is unable to speak, his dialogue consisting entirely of pictures to give an idea as to what he is at least thinking. Through those, it was shown that he does not like his name, had evil thoughts to those who made fun of his name, shows signs of boredom, and could recognize Sonic and Knuckles when they arrived to deal with Hunter. As Knuckles flies over the ruins of Albion in the aftermath of the reborn Enerjak's destruction, Kneecaps sees him in the sky and says "Na-Na!" which could be a name for his older brother. (StH: #140, #141, #186)
Kneecaps is an adorable infant Echinda with red fur and blue eyes and wears a yellow then light blue one-piece suit and unlike his half-brother Knuckles has some hair in the form of a red cowlick.
- Kneecaps is one of a handful of characters to be introduced in the comics as siblings to Sega characters, and the only one whose sibling is present in modern games; Nicolette the Weasel and Matilda the Armadillo's brothers Nack and Mighty haven't appeared in the games for roughly twenty years. Kneecaps is also unique in being the only half-sibling to a Sega character.
- There was a bit of a dispute among writers Karl Bollers and Ken Penders as to what they should name Knecapeon. Karl wanted the name to be Kneecaps, but Ken preferred Mace, and made it canon first in a Mobius:25 Years Later storyline. As a compromise, when Karl wrote Return to Angel Island, he made Kneecaps a nickname.
- Canceled storyline for post #134 issues would have included Locke helping Lara-Le to raise Kneecaps after Wynmacher was sent to the Egg Grapes, a plot rendered impossible by Locke's death.