The Moon is dominated by Ceridwen, the mother of the bard Taliesin, but other Welsh deities such as Arianrhod, Don and Blodeuwedd are also involved with its waxing and waning with Arianrhod being responsible for the full moon. The Moon has always been seen as a female entity.
The familiar shape of the “Man in the Moon” is totally different to the ancient Celts, who see it as a hare or Rabbit in the moon. This is due to the connection between Ceridwen and this animal. In a charming myth, Ceridwen was disappointed by her child Morfran, who was not as good looking as she wanted him to be and was of a dark and ugly disposition. She then heard of a potion that could change her son into a beautiful creature, so she gathered the herbs, got her magical cauldron and lit a fire ready for the brew. Unfortunately, she found that the ingredients had to be stirred in the pot for a year and being the goddess of the Moon, had not time for this.
She employed two young boys to do the job for her, including a child called Dylan, but he got rapidly bored and wandered off leaving the other boy, Gwion to do the job. After stirring and mixing for days on end, Gwion was exhausted and fell asleep. Upon waking, he found the cauldron hissing as the mix was drying and in his haste to get water, his cloak caught the cauldron and pulled it off the fire, spilling the contents across the ground. As he ran after it, trying to save the contents, the last drops fell onto his hands, burned him and he stuck his hand in his mouth, swallowing the last of the potion. This did not make him beautiful as it was not ready, but it gave him the power to change into any form he wished.
Ceridwen heard the commotion and came to investigate, but Gwion took flight across the fields; she saw him and shouted to him. Afraid, Gwion changed into a hare and ran off. Ceridwen used her magic to change into a fox and gave chase. Catching up with Gwion, she just missed him as he jumped into a river and became a salmon and swam away swiftly, she jumped in and became an otter and began to catch him. Knowing that he would be caught, Gwion leaped into a field of wheat and became an ear of wheat. Ceridwen arrived but could not see Gwion, so she changed into a greedy hen and ate all the wheat in the field, including poor Gwion.
The magic in the potion affected Ceridwen and she became pregnant; months later she gave birth to a beautiful baby boy with a “Shining Brow” or beautiful countenance, and so she called him shining brow, or Taliesin in Welsh. Ceridwen and Gwion are inextricably linked as the shape of the hare on the moon when it is full.