E-101 "Beta" was the first main model of Dr. Eggman's E-100 Series robots and one of the most promising. It was created in 3236 and was assigned its first mission of tracking down Froggy by competing against his brothers to find it, but was beaten by E-102 Gamma and then given upgrades to make it more powerful and was sent to guard one of the outposts of the Eggman Empire where he was destroyed by Gamma.
Beta was made as the first 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-102 Gamma, E-103 Delta and E-104 Epsilon, Beta was dispatched to retrieve a frog which had swallowed part of Chaos. While Gamma proved successful in retrieving the right frog, Beta and the others did not, and were beamed away to be disposed of. (StH: #81, #82, SSS: #13)
- In SU: #3, Beta's upgraded design was mistakenly coloured black, white, yellow and red compared to his upgraded black, white and green design in Sonic Adventure. A few other design changes include the optic modules (Beta's final version has a unique green optic design in the games) and the waistplate, which was absent in the comic.
- E-101 Beta replaced the role of E-105 Zeta in the comics, who did not make an appearance at all. Beta was mistakenly colored purple in StH #81, though was clearly marked E-101 in the backstory of StH #82.