Charon is a figure in Greek mythology who ferries souls of the dead across the rivers Acheron and Styx. Acheron is a seven-letter word meaning 'river of woe' and Styx is a four-letter word meaning 'river of hatred'. These two rivers form part of the boundary between the world of the living and the underworld. Charon is often depicted as an old man with a long beard and wings on his hat, and is said to be the only one who can cross the rivers.