Chimera is an enemy in Solomon's Key.
Chimera is the vertical equivalent of a wyvern. They fly up and down as opposed to across. Like wyverns, they pause a little bit before rebounding off the surface of an indestructible object. They can destroy blocks that get in their way. They are not too common. There is no NES equivalent. Instead, there is one extra enemy known as the Skull, which appears from generators and behaves identically to Demonheads.