Echidnas

The Echidnas were the dominant race on Angel Island, and experts in using the Chaos Force which was tied to their patron god Chaos. Though they are survived only by Knuckles the Echidna, remains of their architecture can be found throughout the Central City and Mystic Ruins regions as well as on the Island.

History
When Angel Island was still attached to the mainland the Echidnas were found across the Emerald Coast region of what is now the United Federation, with evidence of major settlements in Sand Ocean, Wild Canyon and what is now called the Death Ruins, in addition to major settlements on now-airborne locations like Sandopolis and Marble Garden. They lived in close proximity to the Black Arms in Glyphic Canyon, with whom they collaborated scientifically, particularly in research of the Master Emerald and Chaos Emeralds.

Echidna society was separated into clans, with the Nocturnus and Knuckles clans being the most influential. The Nocturnus' scientific inclinations and Gizoid robots gave them the highest influence over Echidna society, which the warrior Knuckles' leader, Pachacamac, sought to counter with the raw power of the Chaos Emeralds. Staging a raid on the Altar of the Emeralds, the Knuckles warriors caused the death of several of the Altar's Chao, angering Chaos, who absorbed the power of the Chaos Emeralds himself in order to flood the Echidnas' homeland and nearly wipe out the species.

Pachacamac's daughter Tikal was able to seal Chaos back inside the Master Emerald alongside her own spirit, lifting the remaining Echidnas away into the air and creating what is now the floating Angel Island.