This is another story of Hanuman's birth:
Anjana was an apsara, a celestial dancer, but cursed to be born on earth as a monkey, a shape-shifting monkey able to change her form.
One day Anjana put on a human form and walked across a mountaintop where Vayu, the wind-god, saw her and was captivated by her beauty.
"I am Vayu," he said to her, "and I love you! You will bear my son, and he will be able to move as the wind does, flying as high as he wants."
So Anjana conceived Hanuman, the monkey-son of Vayu the wind-god.
Inspired by: Valmiki's Ramayana
Notes: This is from Book 4: Kishkindha Kanda, sarga 66. Jambavan tells this story to Hanuman in order to make Hanuman aware of his divine powers.