E-103 "Delta" was the third 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, Delta was beamed away to be disposed of. However, Delta was merely re-assigned to a new position within the Eggman Empire at an outpost and later destroyed by a rogue Gamma.
Delta was made as the third 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-104 Epsilon, Delta was dispatched to retrieve a frog which had swallowed part of Chaos. While Gamma proved successful in retrieving the right frog, Delta 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. Delta was assigned to Windy Valley in Soumerca, 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)
- Delta's name was never specified in the comics, though his number was present on his arm. His name comes from the game Sonic Adventure, and is considered tier 2 canon.