I 'did' Medusa 2 years ago - plait hair in as many plaits as it will take without being silly (mine went into 13). Get an alice band/plastic hair band. Get some little rubber snakes (I used 7 x 12" in assorted colours) and attach them with tape or glue to the alice band, making sure they stick out at all angles. Put the alice band on head, with a couple of plaits bent under it so they stick up a bit. Pearly green eyeshadow used as blusher for that snakey sheen, darker green or yellow eyeshadow, purple or dark green lipstick, or glitter lipgloss. A white sheet toga pinned in appropriate places and a pea green over tunic with a green cord belt completed the ensemble and scared a couple of people silly when they came to my door!

LTS