Why Satanists use the goat as a symbol?

Answer 1

Satanists use a pentagram with two points up, often inscribed in a double circle, with the head of a goat inside the pentagram. This is referred to as the Sigil of Baphomet. They use it much in the same way the Pythagorean's did, as Tartaros which translated means pit or void. The Pythagorean Greek lettering is most commonly replaced with Hebrew letters that form the name Leviathan. LaVeyan Stantists use it as a sign of rebellion or religious identification. It's said that the three downward points symbolize the rejection of the Holy Trinity.

Answer 2

Because according to the Holy bible the goat is to satan what the lamb is to god the goat was always considered satans symbol and satanist used and kept most of satans symbolism from The Bible and possibly a few of the other religions.