Slayer is an American thrash metal band founded by guitarists Jeff Hanneman and Kerry King in 1981. Slayer rose to fame as one of the leaders of the American thrash metal movement with their 1986 release, Reign in Blood, which has been called "the heaviest album of all time" by Kerrang!. The band is credited as one of the "Big Four" thrash metal bands, along with Metallica, Anthrax, and Megadeth..