Phears is the main antagonist of the book and film series Mostly Ghostly. He appears in all the films as the main villain as well.
In the Books
Phears's plan is to capture Nicky and Tara Roland, and to rule an army of evil ghosts.
In the Films
Phears plan is to release evil ghosts on Halloween, and capture the Roland children, Tara and Nicky, but fails due to Max saying the chant of the ring.
Phears sends a ghoul to posses Max, but later in the film, the ghoul Emma teams up with him, and they use his cat Maular, to return him to the underworld.
The evil Morgo gives Phears one last chance, he possesses a ghost hunter TV star, and he tries to make Max give him an enchanted crystal, so he can unleash an army of ghosts, but in the end, Max destroys the crystal.