Warriors: Omen of the Stars #1: The Fourth Apprentice Hardcover – Illustrated, November 24, 2009

by Erin Hunter (Author), Owen Richardson (Illustrator), Allen Douglas (Illustrator)

Warriors: Omen of the Stars #1: The Fourth Apprentice Paperback – Illustrated, November 3, 2015

by Erin Hunter (Author), Owen Richardson (Illustrator), Allen Douglas (Illustrator)

The Fourth Apprentice: Warriors: Omen of the Stars, Book 1  Audible Audiobook – Unabridged

Erin Hunter (Author), MacLeod Andrews (Narrator), HarperCollins (Publisher)

Warriors: Omen of the Stars #1: The Fourth Apprentice Kindle Edition

by Erin Hunter (Author), Owen Richardson (Illustrator), Allen Douglas (Illustrator)  Format: Kindle Edition