Start with high-confidence mythical creatures books, then narrow by subgenre or adjacent topics.
Creatures of the in Between
Cindy Lin
Anya and the Dragon
Sofiya Pasternack
Dealing With Dragons
Patricia C. Wrede
Wings of Fire: the Dragonet Prophecy: a Graphic Novel (wings of Fire Graphic Novel #1)
Tui T. Sutherland, Mike Holmes
Paper Dragons
Siobhan McDermott
Impossible Creatures
Katherine Rundell, Ashley Mackenzie
The Poisoned King
Quest for the True Dragon: a Graphic Novel (city of Dragons #3)
Jaimal Yogis, Vivian Truong
The Dragon and the Stone, Volume 1
Kathryn Butler
Unicorn Crush
Dana Simpson
The Paper Bag Princess (classic Munsch)
Robert Munsch, Michael Martchenko
Dragonborn
Struan Murray