Nathaniel Fludd, Beastologist is an ongoing series of chapter books for children written by Robin LaFevers and illustrated by Kelly Murphy.

The books chronicle the adventures of young Nathaniel "Nate" Fludd, a beastologist in training who travels the world in search of mythical beasts, with his mentor Aunt Phil and pet gremlin Greasle.

Despite initial fears that he would end in the care of his cruel governess Miss Lumpton, Nathaniel is thankfully taken under the wing of a distant cousin, Aunt Phil (short for "Philomena"), the world's last beastologist.

Soon Nate embarks on his first voyage, following Aunt Phil to Arabia to aid and witness the world's only Phoenix as it prepares to lay its new egg.

Wyverns, giant dragons dwelling the Welsh countryside, are in an uproar and threatening to break an oath of peace with humans.