Status Updates From Mystery Cats of the World

this is very down-to-earth, he focuses on a lot of mystery cats that can be explained as either out-of-place existing species or very rare mutant variations of well known animals that just aren't known yet rather than completely new animals

I'm genuinely convinced now that there might be breeding populations of jaguars, leopards, pumas and whatnot in the UK and might have been so ever since the 16th century when having private menageries of exotic beasts became popular among the British upper class - Shuker makes a much better case for this than most other cryptozoologists.

this starts with quite a bit of information about feline biology and the history of various big cats that did inhabit Britain during the pleistocene, you can tell the author's one of the cryptozoologists with genuine expertise in mainstream zoology