It looks like Assassin's Creed Odyssey is the name of the new Assassin's Creed game from Ubisoft. The latest leak comes from French gaming site, Jeux Video, who show a collectible keyring featuring a spartan helmet as proof.
In the picture below, you can see this collectible gift is labelled - Assassin's Creed Odyssey. “The spartan-shaped keychain leaves little room for doubt and that is why we can say that the action will most likely make us travel to ancient Greece in this episode,” writes the author.
Earlier rumors suggest that Assassin's Creed Odyssey will feature both a male and female protagonist, see players fighting against Greek mythological creates and will be set after the events in Assassin's Creed Origins. These rumors have not been confirmed.
Currently, Assassin's Creed Odyssey, which is rumored to be codenamed Dynasty, hasn't officially been confirmed, but we'd expect Ubisoft to reveal it at E3 2018.
Earlier this year, Walmart listed a new untitled Assassin's Creed game for release in 2018, though we wouldn't be surprised if we don't see the next entry in the series until 2019.