The X-Files: The Official Archives: Cryptids, Biological Anomalies, and Parapsychic Phenomena by Paul Terry.
From Abrams Books:
"A fully authorized, richly illustrated inside look into 50 of Mulder and Scully’s most memorable monster cases
When an X-Files fan opens up The X-Files: The Official Archives, they are gaining access—for the ﬁrst time—to Agents Mulder and Scully’s notes, records, and visual evidence from actual X-File reports. Designed to mimic a collection of FBI case ﬁles and packed with such items as autopsy reports, mug shots, lab results, handwritten notes, newspaper clippings, pages ripped from antique books on the occult, and security camera printouts, this fully authorized book is the only one of its kind. Detailing the agents’ investigations into 50 cases of cryptids, biological anomalies, and parapsychic phenomena—from the Flukeman to The Great Mutato to Pusher—The X-Files: The Official Archives showcases some of the show’s greatest villains (some dastardly, some just misunderstood), and instructs future agents on how to successfully investigate the paranormal."
(Over the Counter is a regular feature at A Bookworm's World. I've sadly come the realization that I cannot physically read every book that catches my interest as it crosses over the counter at the library. But...I can mention them and maybe one of them will catch your eye as well. See if your local library has them on their shelves!)