The goat has long been used in heavy metal on album covers, in band names and in lyrics. But many metal fans fail to realize its significance and why its imagery is used in metal. Matthew 25:31-33: "the Son of Man... will separate the people one from another as a shepherd separates the sheep from the goats. He will put the sheep on his right and the goats on his left," the goats presumably headed for eternal damnation. The preachers say this is because sheep are obedient whereas goats are ornery and do their own thing. Also, goats have very prominent genitals, while sheep are sheepish.
All that having been said, the connection between Satan and goats is indirect. The goatlike features commonly attributed to the devil derive from the Greek pastoral deity Pan, who was half man, half goat. If you take away Pans flute and give him a pitchfork, you'd think he was the devil.
Origins of "Throwing the Goat"
In Hinduism and Buddhism, this gesture is known as the Karana Mudra. Its use in dispelling evil or negative influences is a noticeable juxtaposition to the contemporary uses of this sign.
Chicago-based psychedelic-occult rock band Coven, led by singer Jinx Dawson, whose 1969 back album cover for Witchcraft Destroys Minds & Reaps Souls on Mercury Records pictured Coven band members giving the "sign of the horns" correctly and included a Black Mass poster showing members at a ritual making the sign. Starting in early 1968, Coven concerts always began and ended with Jinx giving the "devil's sign" on stage. Incidentally, the band also recorded a song called "Black Sabbath," on their 1969 album and one of the band members is named Oz Osborne, not to be confused with Ozzy Osbourne of Black Sabbath. The horns became famous in metal concerts very soon after Black Sabbath's first tour with Dio.