There is more than one artist with this name:
1) Annihilator is a technical speed/thrash metal band which started with the album Alice in Hell, and now has sixteen albums (including live albums and best of-albums).
Annihilator was started in Ottawa by Jeff Waters in 1984. He wrote and recorded a song with singer John Bates called "Annihilator" which was released on disk as a bonus-track for a special edition of "All For You" and as a bonus-track for limited editions of "Schizo Deluxe" albums. Waters recruited a drummer named Paul Malek and Bates found a bassist named Dave Scott (Richer). This lineup lasted two years, and these earlier tracks made up a good part of the band's first two albums. Before the release of their debut LP, John Bates and Dave Scott decided to leave the band, citing artistic differences and personality conflicts. Waters relocated to Vancouver where he assembled a whole new line-up, including former D.O.A. member Randy Rampage. Waters has shuffled his line-up, including singers, throughout Annihilator's run.
2) Annihilator is a deprecated moniker sometimes used by Scott Brown when he used to produce gabber tracks.