Dragons, Dragons, and Other Creatures that Never Were by Eric Carle, 1991.

This is a collection of poems and quotations about various mythical creatures from around the world. The poems and quotes come from various sources. Some are by famous authors and some are nursery rhymes and pieces of folklore. The quote about the leviathan is from The Book of Job.

The illustrations are what really make the book interesting. They are bright and colorful, and the middle section of the book folds out to reveal a particularly long picture of a Chinese dragon.

Although there are common mythological creatures, like dragons, unicorns, yetis, the phoenix, there are also less common ones that some children may not have even heard of, like the giant bird called the roc, the two-headed amphisbaena, the kappa, and the bunyip.

Most of the descriptions of the creatures are in the poems themselves and in the accompanying pictures, but there is a glossary in the back that explains more about what each creature is and where it is from.

The book is available to borrow and read online for free through Internet Archive (multiple copies).