With snakes for hair and a face more likely to sink a thousand ships than launch them, Medusa’s head was a popular apotropaic symbol (a talisman against evil). This mosaic Medusa occupies the panel to the right of the Tethys panel in the triclinium. According to Greek mythology, anyone who gazed upon this daughter of sea deities would turn to stone. Using his polished shield as a mirror in order to avoid looking at her, the mythological hero Perseus slew Medusa and took her head as a prize.