Scorpio is the eighth sign, a fixed water sign, traditionally ruled by Mars and in modern astrology also associated with Pluto, with the Scorpion as its emblem. The scorpion is one of the oldest figures in the zodiac, attested in Babylonian cuneiform star lists many centuries before Greek astrologers adopted a written shorthand for it. That shorthand, the compact glyph now used for Scorpio, first appears alongside the rest of the zodiacal notation in the Greek horoscope papyri of Roman Egypt, ordinary documents catalogued by Otto Neugebauer and Henry Van Hoesen in their reference work Greek Horoscopes, was copied through the medieval Byzantine manuscript tradition, and only settled into its familiar printed shape during the Renaissance, when printers standardised the sign glyphs across successive editions of the almanacs.
Scorpio's Unicode codepoint is U+264F, one of the twelve consecutive zodiac symbols the standard placed in the Miscellaneous Symbols block, two hundred fifty-six codepoints in all spanning U+2600 to U+26FF, when that block was introduced in version 1.1 in 1993. The scorpion also lends its name to the star Antares, whose Greek name means rival of Mars, a comparison ancient writers drew from the star's reddish colour.