Scorpio Series by Alex McDonough, Janet Fox

Savage Hunters are tracking the alien known as Scorpio. The chase has crossed two planets and thousands of years, and the Hunters are finally catching up. In a last, desperate gamble, Scorpio flees blindly through time with his only ally: a human girl named Leah de Bernay, a fugitive in time from the 14th century... moreSavage Hunters are tracking the alien known as Scorpio. The chase has crossed two planets and thousands of years, and the Hunters are finally catching up. In a last, desperate gamble, Scorpio flees blindly through time with his only ally: a human girl named Leah de Bernay, a fugitive in time from the 14th century. From a Russia on the eve of revolution to the age of the dinosaurs, and back to the killing fields of 20th century Cambodia, the time travelers race to stay one step ahead of their pursuers while Scorpio searches for a way to save his people from extinction less