The Cage has been (unwillingly) inhabited by many races during its history. The first inhabitants of which any records remain are the "Precursors", who shared the dimension with a variety of unnamed species. When Sonic and his friends arrive in the Cyclone during Sonic Chronicles, the eldest race residing there is the Kron. Alongside them are the Zoah, the N'rrgal, the Voxai, and the Nocturnus Clan echidnas.