Bixi is one of the 9 sons of the Dragon King. He can be seen in the architecture in China propping up supports of buildings.
Puca is a shape-shifter. In this image he's in the middle of changing from a 6-foot rabbit (much like Harvey the Rabbit) into a kelpie (water horse spirit).
In Serbian lore, the dead are usually lain beside a wall so animals are not able to jump over the body. In this sketch, the body was not lain near a wall, and a dog was able to jump over it. Therefore this body became a vampire.