Rutan the Echidna - Sonic Archie Comics

Dr. Finitevus - Sonic Archie Comics

Dr. Zachary - Sonic Series

Zeta the Echidna - Sonic Series

Athair the Echidna - Sonic Series

Gae-Na The Echidna - Sonic Series

Echidna - Witch of Greed - Re:Zero

Lara-Le The Echidna (Knuckles' Mom)

Mari-An The Echidna

Lara-Le - Sonic Series

Locke the Echidna - Sonic Series

Lara-Su The Echidna - Sonic Archie Comics

Pachacamac the Echidna - Sonic Adventure

Aurora the Echidna - Sonic Archie Comics

Echidna - Monster Girl Encyclopedia (MGE)

Julie-Su The Echidna - Sonic Archie Comics

Pachacamac (from Knuckles, Sonic Cinematic Universe)

Shade the Echidna - Sonic Series

Tikal the Echidna - Sonic Adventure (Pony/Illustrious)

Gala-Na the Echidna - Sonic Archie Comics