This transformation exists primarily within the Sonic X continuity.
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
Serpenter, also known as E-38 Neo in Japan, was a combined robot in the Sonic X anime series. It is formed when Doctor Eggman's numerous amounts of E-39 Quizons merged.
New World Saga
The Serpenter was formed by Eggman to combat Sonic the Hedgehog when he arrived to foil his plans. However, the Serpenter destroyed a good luck bracelet Amy Rose made for Sonic, throwing her into an extraordinary wrath. She tore the Serpenter apart in vengeance.