Re-reading the Garret, P.I. series, I found this passage I always liked:
"Unicorns, vampires, mammoths, fifty kinds of thunder lizards, werewolves, and countless other creatures often deemed mythical I had seen with my own eyes. [. . .] But these flying horses and the bitty bowman [a cherub] constituted my first encounter with a class of creatures I thought of as artist's conventions. Symbols. These guys, griffins, ostriches, cameleopards, cyclops. All of them supposedly as uncommon as a lawyer driven only by a need to see justice done."
- Glen Cook, "Petty Pewter Gods."
In a mythical world - a world full of monsters - what beings are actually myths? Earth is covered with truly remarkable species, yet we've imagined a whole menagerie of creatures that don't exist. What kind of things do people in a world of strange monsters imagine? What normal creatures can you set off on such a list in order to drive home the strangeness of the world to real-world players?