Annihilator is a Canadian thrash metal band founded in Ottawa in 1984 by Jeff Waters. Waters is the band's sole constant member and has acted as its guitarist, bandleader, writer, producer, engineer, and occasional bassist and vocalist. Annihilator has released seventeen studio albums and has undergone many line-up changes, with Waters regularly assembling touring or session musicians to perform with him. Along with Sacrifice, Voivod and Razor, Annihilator has been referred to as one of the "Big Four" of Canadian thrash metal. They are also considered to be part of the "second wave" of thrash metal bands from the late 1980s and early 1990s.