Amy Rose

Amy Hedgehog is a major character in the Sonic Hedgehog Series and is the highly intelligent and spirited younger sister of Sonic Hedgehog. She often aids her big brother by building gadgets ideal for the situation or even tagging along with him in his journeys, using self-taught martial arts to defend herself. She first appeared in the first game. Her first appearance as a playable character was in Sonic Hedgehog 2: Eggman Strikes Back. Since then, she has appeared in every Sonic game.

Just as her brother was, Amy was an ordinary Hedgehog until she was taken from the jungle and genetically enhanced by Doctor Ivo Robotnik and Doctor Heinz Doofenshmirtz to conquer the world, but, just as Sonic, she rebelled.

Sonic Hedgehog 2: Eggman Strikes Back
Amy is first seen in Sonic Hedgehog 2: Eggman Strikes Back living on Insanity Island with Sonic. One day, when the battery for her laptop runs out, she sends Sonic off to find a replacement battery for her. When Amy discovers that Sonic is gathering crystals for Eggman, she becomes suspicious of Robotnik and decides to hack into his computer to see what he's really up to. What she finds are detailed schematics for an improved Robotnik Sputnik and a suspicious-looking space station. She learns of Eggman's real plan, just as Sonic has gathered all the crystals, and reveals Eggman's intentions to Sonic before he can give the crystals to Eggman.