Thunder

Thunder was created in the middle of the Mobian Desert from a lightning bolt hitting a stray quill of Sonic the Hedgehog, awakening in the resulting geode. He had no recollection of who he was or where he came from, except that he was surrounded by lightning, and as one hit him, he felt comfortable, and even stronger. So the name Thunder stuck to him. He wandered that desert, instinctively looking for a home. He saw a trashed base of Eggman, drawn to it by its electronics. As he tried to access a database, he got images of Eggman, Sonic & his friends, and other things, including how to make robots. However, the look of the robots repulsed him, so he impulsively made the robots, and eventually the base itself, to his liking. When he was done, the base looked nothing like Eggman's making.

For a while, he grew up, using the computers and robots to get him what he needed. Then, he began to see the other places on Mobius, and wonder what it would be like to venture to those places and meet those people. As he began to see the images of girls, a feeling he never knew he had began to grow: sexual arousal. Wanting to know more, Thunder began to make transports for land, air, and sea and in-between, going out into the world to see what it had to offer him. Perhaps he could figure out where he came from.

Ever since he discovered that Eggman was using a process called roboticization to make animals & Mobians his slaves, Thunder has been working on a reversal process to undo this. In the meantime, Thunder has offered sanctuary to Robians wishing security & freedom until he can undo the roboticization. 

Thunder is fascinated with computers, robots, technology, and the capabilities thereof, and thus is constantly working on them. Due to his interest of girls, he often uses female bodies & voices in AIs & robots, using synthetic skin & parts for the robots and making graphics for the AIs.

Thunder knows absolutely nothing about females, and his curiosity knows no limits, so he tries to talk to different females to learn, discovering his likes and dislikes, to trial and error.