From Ovid's "Metamorphoses", Book XIV:

She saw us then and, salutations made,
Her welcome seemed an answer to our prayers.

At once she bade the servants mix a brew
Of roasted barley, honey and strong wine
And creamy curds, and then, to be disguised
In the sweet taste, she poured her essences.
We took the bowls she handed (magic hands!).
Our throats were dry and thirsty; we drank deep;
And then the demon goddess lightly laid
Her hand upon our hair, and instantly
Bristles (the shame of it! but I will tell)
Began to sprout; I could no longer speak;
My words were grunts, I grovelled to the ground,
I felt my nose change to a tough white snout,
My neck thicken and bulge. My hands that held
The bowl just now made footprints on the floor,
And with my friends that suffered the same fate
(Such power have magic potions) I was shut
Into a sty...