every known one? Lol
Maybe Cryptozoology A To Z is an idea?
Cryptozoology A to Z by Loren Coleman is a good choice.
Still in Search of Prehistoric Survivors by Karl Shuker is a great book about modern sightings of alleged prehistoric creatures.
The Field Guide to Lake Monsters and Sea Serpents is a great overview of marine cryptids.
The Journal of Cryptozoology by Karl Shuker is also a really good choice. They’re short books, but they focus on current research in cryptozoology.
Loren Coleman’s Cryptid book is a good start Cryptozoology A To Z: The Encyclopedia of Loch Monsters, Sasquatch, Chupacabras, and Other Authentic Mysteries of Nature https://www.amazon.com/dp/0684856026/ref=cm_sw_r_cp_api_glc_i_fUQaGbPAV8E3A
Cryptozoology A to Z by Loren Coleman? https://www.amazon.com/Cryptozoology-Encyclopedia-Sasquatch-Chupacabras-Authentic/dp/0684856026
Try cryptozoology A-Z by loran Coleman http://www.amazon.com/Cryptozoology-Encyclopedia-Sasquatch-Chupacabras-Authentic/dp/0684856026