Villain's Food and Fuel

Even great villains need to quench their appetites. In many a story, there comes a time when a villain or dark entity consumes something (human flesh, blood, magic potions, food, etc.) or gives that to someone else. This can happen for many reasons:
 * To satisfy his/appetite for blood
 * To obtain superpowers
 * To turn someone over to the dark side
 * To transform into a more powerful entity
 * To create a disguise

Noteworthy examples

 * The Wicked Queen drinks a magic potion to transform herself into an old crone to deceive Snow White.
 * Erich Ludendorff inhales a special serum to enhance his strength.
 * Polyphemus devours some of Odysseus's men to satisfy his taste for human flesh.
 * Poppy Adams grinds one of her henchmen alive and turns him into a hamburger.
 * Hannibal Lecter is notorious for killing and devouring humans.
 * Muriel and her coven kidnap children to sacrifice and devour.
 * Norman Osborn takes in a serum to transform into the Green Goblin.
 * Krudsky obtains the power of the Goblin Scepter in a bid to take over the world.
 * Evanora gives Theodora a magic apple to turn her over to the dark side.

Quotes
"The only thing we serve here is tongue."

- Mama Fratelli to the Goonies when she captures Mikey. "(Muriel and her coven have captured a boy to sacrifice.) He is ready. (Muriel's goons place the boy down on an altar. She smiles evilly, pulling out a huge cleaver. Muriel gives it a small twirl and raises it above her head.) RAHRRRRR! (After Muriel kills the boy with a well-placed blow, her coven slurps up cups filled with the blood and meat of their captive.)"

- Muriel and her coven killing a boy to devour.