The Little Bull-Calf
Also included within The Red King and the Witch: Gypsy Folk and Fairy Tales by Ruth Manning-Sanders and A Book of British Fairy Tales by Alan Garner.
A little boy was given a little bull-calf by his father. His father died, and his mother remarried. His stepfather was cruel to him and threatened to kill the calf. An old man advised the boy to run away, and he did. He begged for some bread, which he shared with the calf. Later, he begged for some cheese, which he would have shared, but the calf refused. It told the boy it would go into the wild and kill all the creatures it finds, except a dragon, which will kill it. It told the boy to climb a tree, and once it was dead, to skin it and take its bladder, which would make anything it struck drop dead. With it, he was to kill the dragon.
It happened as the calf said. Monkeys climbed the tree after him, and the boy squeezed the cheese, claiming it was flint; when they saw the whey, they retreated. The boy set out to find the dragon and kill it. He found a princess who had been staked out for the dragon. He killed it, though it bit off his forefinger. He said he must leave her, but first he cut out the dragon's tongue and the princess gave him a diamond ring. The princess told her father, who asked for him to come, and many gentlemen cut off their forefingers and brought diamond rings and the tongues of all kinds of beasts, but none were the dragon's tongue or the princess's ring.
The boy came, but the king turned him away as a beggar, though the princess knew he was like the boy. Somewhat later, he came back, better dressed, and the princess insisted on speaking with him. He produced the ring and the tongue and married the princess. And they lived happily ever after.