Sonic the Hedgehog's super transformation. He accesses this state by collecting all the seven Chaos Emeralds, which in turn grants him exponential speed and power increases, flight abilities and immunity to most attacks, becoming nearly invincible when doing so.
In most games, Sonic must retain a certain amount of rings while in this state (usually having to collect 50 rings to access it), otherwise he'll revert back to his regular state.
This transformation is also widely viewed as an homage to Dragon Ball Z and the Super Saiyan transformations.
