S is for… Shuyu

One of the many denizens of the Guideways, the Shuyu is a four-headed (or four-eyed) cawing red chicken with six feet and three tails. Eating it cures melancholy.
R is for… Rosmaputh

The Rosmaputh is a hideous creature found in the Caspian Sea. It has a man’s head covered with bristles and armed with long sharp teeth. It has a long neck, scaleless skin, broad shoulders, and flippers that reach to the tail. Its tongue is shaped like a laurel leaf. When out of the water it screams nightmarishly.
in awe at the size of that beaver

There’s a good reason why it’s front half horse, back half alligator and not the other way round
Sadly I will never be able to top Lewicki’s rendition of the alligator-horse, published in the LIFE Treasury of American Folklore.

I always thought the Protoceratops-griffin connection was unrealistic, but this does a way better job of taking it apart than I ever could!

Worth including in ABC? The dreaded alligator horse of Kentucky.
O is for… Opimachus

The chargol insect of Leviticus begat the ophiomachus (“snake fighter”) of the Septuagint, by way of Aristotle’s account of snake-eating locusts. This in turn begat the opimachus of the Ortus Sanitatis, which merges it with the snake-fighting secretary bird. Did it beget the word “opinicus” as well?