E-104 "Epsilon" was the fourth of the E-100 Series droids created by Dr. Eggman in 3236. Its first mission was to retrieve a frog that swallowed part of the mutated Chao known as Chaos. But it failed and E-102 Gamma succeeded, and as a result, Epsilon was beamed away to be disposed of. However, Epsilon was merely re-assigned to a new position within the Eggman Empire at an outpost and later destroyed by a rogue Gamma.
Epsilon was made as the fourth unit of Dr. Eggman's E-100 Series (excluding E-100 Alpha) in 3236 with his design apparently based off that of the Alpha 100 Series Mechanoid Isaac, who was created by his master's Prime counterpart's ancestor, Dr. Ivan Kintobor. (StH: #81, #82, #146, #147, #148, #149 SSS: #13)
First Mission: Search for Froggy
Along with E-101 Beta, E-102 Gamma and E-103 Delta, Epsilon was dispatched to retrieve a frog which had swallowed part of Chaos. While Gamma proved successful in retrieving the right frog, Epsilon and the others did not, and were beamed away to be disposed of. (StH: #81, #82, SSS: #13)
Following the Chaos incident, Dr. Eggman reassigned the surviving E-100 series robots to various outposts throughout the Eggman Empire. Epsilon was relocated to Red Mountain on Angel Island, where the rogue robot E-102 Gamma, which had tasked itself with tracking down and destroying the surviving E-100 robots, found and destroyed him. (SU: #3, ASUB)
- In the Sonic Adventure videogame, E-104 Epsilon had two arm cannons like E-103 Delta after he was rebuilt, whereas in the comics he was only shown with one arm cannon. Additionally, Epsilon's name was never specified in the comics, though his number was present. His name comes from the game Sonic Adventure, and is considered tier 2 canon.