Delta was created as one of Doctor Eggman's E-100 Series. After failing to capture Froggy, Eggman ordered Delta to be destroyed, but he somehow escaped. E-102 Gamma later found him and deleted his master, shutting him down and releasing the rabbit inside.
|Heroes||Sonic | Tails | Amy | Knuckles | Cream | Cheese | Chris | Big | Tikal | Vector | Espio | Charmy | Cosmo|
|Neutral/Anti-hero||Shadow | Rouge | Chaos | Emerl | Gamma | Zero | Beta | Delta | Epsilon | Zeta|
|Villains||Eggman | Decoe and Bocoe | Bokkun | Biolizard/FinalHazard | Dark Oak | Red Pine | Yellow Zelkova | Pale Bay Leaf | Black Narcissus|
|Groups||Chao | Metarex | G.U.N. | E-Series | Team Sonic|
|Miscellaneous||Gerald Robotnik | Maria | Vanilla | Molly | Hertia/Earthia | Galaxina | Nazo|
|Transformations||Super Sonic | Super Shadow | Dark Sonic | Final Nova | Cosmo's transformation|