Multiverse Sonic - sprite sheet by Swagboy567 on DeviantArt

Custom Sonic Sprite Sheet by TaymenTheHedgehog on DeviantArt

Pixilart - sonic simple sprite sheet by Tuxedoedabyss03

ArtStation - Sprite accurate Sonic The Hedgehog (16 bits).

Porting Sonic's Sprites from Sonic 3 to Sonic 1

NFG Games Presents - A Sonic the Hedgehog Sprite History

Accurate Sonic 1/CD Sprites

Custom / Edited - Sonic the Hedgehog Customs - Sonic (Sonic 1 Beta-Style) - The Spriters Resource

Sonic the hedgehog: Blue trouble – The adventures of Jesse and Sonic

Sonic 3(Sonic 2 style) sprite sheet by souptaels on DeviantArt

i made the sonic 1 sonic sprite in mania style! : r/SonicTheHedgehog