|Featured in||Sonic Adventure|
E-101 Beta is a robot created by Dr. Eggman as part of the E-series. Eggman describes Beta as E-102 Gamma's "big brother", presumably as they have a similar design and Beta, judging by his series number, was created first. Beta and Gamma were pitted against each other by Eggman in order for him to decide who would go on to serve him, ultimately Gamma was the victor.
Beta appears as a boss twice in Gamma's storyline.
 Boss Strategy
Beating Beta is a simple matter of dodging his homing missiles and hitting him 3 times with your own.
 E-101 MkII
As Gamma's storyline progressed, Beta was upgraded to E-101 MkII with improved weaponry and the ability to fly. Beta fought against Gamma a second time but again lost against Gamma. Using the last of his strength, Beta shoots Gamma just before his power goes out, destroying Gamma and releasing the Flicky bird trapped inside Gamma, his own Flicky being released at the same time.
 Boss Strategy
This time, if you target him at the start he will simply send the missiles back at you. When Beta attacks you with his own homing missiles, destroy them. When you see that E-101 is targeting you and preparing his attack (light appears around him), get behind him and shoot him before he attacks you. That's the only time when you can hit him. After 2 hits like that, he'll go up at the top of the screen and shoot 1 missile at you so avoid it. Then, E-101 will reappear on the field so do as before to hit him. The last time, he'll fly up and shoot a lot of missiles at you. Avoid them all and finally hit him for the last time. Four hits total to destroy him.