The One Billionth Power Ring is an object that appears in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics. It is the one billionth Power Ring that Sonic the Hedgehog grabbed, a milestone the Ancient Walkers rewarded by granting his one billionth Power Ring with more energy than any other.
As soon as Sonic the Hedgehog took hold of his one billionth Power Ring, it transported him though a ring tunnel and into the Zone that the Ancient Walkers created. There he met the first Ancient Walker standing on a giant Power Ring. Sonic dropped the ring, because it was heating up, and burned a hole into the ground. The circle in the center then rose up with Sonic on it. After a brief talk with the Ancient Walker, the circle dropped and Sonic fell back onto his ring which was now the size of an inner-tube. Sonic was surprised to find that he was floating on a sea of Chaos Emeralds and that another Ancient Walker was sitting right next to him. He gave Sonic a riddle to answer and he answered it correctly.
The Walker then raised a ring chain out of the sea which pulled Sonic under it. Sonic is hanging by the chain, when he sees his billionth ring again. This time, the ring grows big enough for Sonic to jump into it. The ring starts spinning, and Sonic runs as fast as he can to keep up. The ring then warps into the shape of an infinity symbol. Sonic then meets the third Ancient Walker which grants him a question to ask. Sonic stupidly asks if he gets just one question and the Walker takes it as his final answer. Sonic mutters that it wasn't fair as the ring shrinks back to its normal size and takes him out of the zone. He arrives back where he came from slicing through Dr. Ivo Robotnik's Egg-Pod as he lands. He then takes it back to Knothole and frames it. He shows it to Sally Acorn while telling her that he is determined to find the origin of the Rings and Chaos Emeralds, because he believes that they hold the key to freeing Mobius from Robotnik's rule.
It was revealed that the one billionth ring created an inner shield to keep a little bit of Sonic free will when he was roboticized into Mecha Sonic. Although the shield did not prevent roboticization, it helped deroboticize him when Nicole accessed it to restore his free will.