E-105 Zeta was a purple E-100 Series robot.
Zeta was the sixth E-Series robot created by Dr. Eggman. At some point it was retrofitted into a restorative engine in the remains of the Egg Carrier, but it was found and destroyed by E-102 Gamma and its Mobini freed. (ASUB)
- Zeta made his debut appearance in the Sonic Adventure video game, but was absent from the comic adaptation, his role filled by E-101 Beta. His fate in the Pre-Super Genesis Wave continuity was revealed in the (now defunct) Sonic Universe blogs.
- Zeta shared his serial number with the unrelated E-105 Series in the Pre-Super Genesis Wave continuity.