It's Baphomet. In earlier renditions it was a dragon. Generally a god of knowledge and healing.
Although as with most things not christian in the wake of christianity's expansion, it became a symbol adopted by those who wanted to be angsty toward the church and of course the church declared everything not theirs to be satanic.
So then people, be they edgelords or genuinely evil, started conflating all of that with actual satanic practices.
Few things created more shadows for evil to hide in than the church.