Lamia is an epic poem by Romantic poet John Keats, written in two parts. Lamia is a serpent-like monster who can disguise herself as a female. In the first part of the poem, she finds herself trapped in a serpent’s body when she encounters Hermes, who searches for a nymph who is hiding from him. Lamia, trapped in a serpent’s body, makes the following proposition to Hermes:

'I was a woman, let me have once more
A woman's shape, and charming as before.
I love a youth of Corinth--Oh the bliss!
Give me my woman's form, and place mew here he is.
Stoop Hermes, let me breathe upon thy brown,
And though shalt see thy sweet nymph even now.' (117-121)

She asks him to restore her female form, and in exchange she will reveal his beloved nymph to him. Though Lamia is known to be a monster, Keats’ portrayal of her is apologetic. He says:

Her head was serpent, but ah, bitter-sweet!
She had a woman's mouth with all its pearls complete:
And for her eyes: what could such eyes do there
But weep, and weep, that they were born so fair?" (59-63)

At the poem's end, Lamia succeeds in wedding her beloved mortal, Lycius; however, the philosopher Apollonius attends, and he sees through Lamia's disguise. He calls Lycius a fool, and says:

'-from every ill
Of life have I preserv’d thee to this day,
And shall I see thee made a serpent’s prey?' (296-9)

After being called a serpent by Apollonius, Lamia vanishes, and Lycius dies.