Medieval Arthurian Legend
Old French pre-Vulgate Lancelot
13th century, Old French.
The boys became the greyhounds and the greyhounds took on the appearance of the boys.
'Lancelot's two cousins, Lionel and Bors, have been smuggled into the land beneath the lake,' said Miranda, 'in the guise of two greyhounds. It happened like this: the boys were being held against their will in a castle, and the Lady of the Lake sent one of her damsels, leading two greyhounds, to the man who was holding the boys prisoner, and when a fight broke out in his hall, she was able by her magic to swap them around; the boys became the greyhounds and the greyhounds took on the appearance of the boys. Look: the man holding them prisoner is called Claudas, and
Claudas comes after them, whereupon Saraide's enchantment makes the boys look like greyhounds, and the two hounds like the boys.
'The damsel then flees with the greyhounds and takes them beneath the lake, while the two boys are recaptured. They all turn back into their proper shapes in the evening.'