While the Greek gods could use transformation punitively -- as for Arachne, turned to a spider for her pride in her weaving, and Medusa, turned to a monster for having sexual intercourse with Poseidon in Athena's temple -- even more frequently, the tales using it are of amorous adventure. Zeus repeatedly transformed himself to approach mortal women, both as a means of gaining access:

• Danae as a shower of gold
• Europa as a bull
• Leda as a swan)
• Calllisto as Artemis, after which either Hera or Artemis punatively transformed Callisto into a bear or to attempt to conceal his affair from Hera
• Io, as a cloud, and Io herself as a white heifer.

In one tale, Demeter transformed herself into a mare to escape Poseidon, but Poseidon counter-transformed himself into a stallion to pursue her, and succeeded in the rape.

In other tales, the woman appealed to other gods to protect her from rape, and was transformed (Daphne into laurel, Cornix into a crow). Unlike Zeus and other god's shape-shifting, these women were permanently metamorphosed.

Humans were also transformed, for many reasons.

Tiresias once saw two snakes mating and struck the female with his staff; this transformed him into a woman, and he lived as such for many years. At the end, he saw the snakes again, and this time was careful to hit the male, which restored him to male form.

Caenis, having been raped by Poseidon, demanded of him that she be changed to a man. He agreed, and she became Caeneus, a form he never lost, except, in some versions, upon death.

As a final reward from the gods for their hospitality, Baucis and Philemon were transformed, at their deaths, into a pair of trees.

Pygmalion having fallen in love with a statue he had made, Venus had pity on him and transformed the stone to a living woman.

In some variants of the tale of Narcissus, he is turned into a flower.

After Tereus raped Philomela and cut out her tongue to silence her, she wove her story into a tapestry for her sister, Tereus's wife Procne, and the sisters murdered his son and fed him to his father. When he discovered this, he tried to kill them, but the gods changed them all into birds.