Dark Oak is a fictional villain from the Sonic X cartoon series. He is the leader of the Metarex, an army of bio-robots that scours the galaxy for the Planet Eggs, jewels that contain the life energies of the planets. Dark Oak has one large, green eye and carries a golden sword. Sonic X is the newest Sonic the Hedgehog animated series, based roughly on the storylines of Sonic Adventure series. ...

Dark Oak first appears to challenge Super Sonic in orbit around Mobius. Despite Super Sonic's seeming invincibility in his previous battles, he is unable to defeat Dark Oak. In order to prevent Oak from stealing the Chaos Emeralds, Sonic uses Chaos Control to send them away. As Sonic falls toward the planet, Oak departs for space, revealing damage that Sonic had not noticed. His final act in that incident was to alert his forces to search for the Chaos Emeralds and to send a Metarex to remove Mobius' Planet Egg. This page is about the video game character Super Sonic. ... A Chaos Emerald is a mystic item that appears in the Sonic the Hedgehog video games, allowing the holder of all seven of them to transform into a super form (see Super Sonic). ...