Finchingfield Dragons

This fine dragonesque reptile lives in Finchingfield . How long he has been scratching at the walls is anyone's guess, and getting his blood to flow would be (quite literally) like getting blood out of a stone.

Of course in real life, Dragon's blood is a plant product, a resin. It is still used in topical skin preparations and to varnish violins!
Let me draw around him to make the graffiti a little clearer. I thought he was a cockatrice to start off with. But cockatrice's are generally depicted with two legs and not four.

He might be a basilisk, The basilisk is alleged to be hatched by a cockerel from the egg of a serpent or a toad (as opposed to the cockatrice who is hatched from a cockerels egg by a serpent or a toad (are you keeping up here?). 
Let's split the difference and call him a Basilicok; that'll cover both bases and give Chaucer a nod at the same time ..."The basilicok sleeth folk by the venym of his sighte".

The vicar of Finchingfield tells me that the screen adjacent to the graffiti is 15thc in construction. Look at this little device. Another dragon, but this time with human legs and feet!