There are at least 4 bands named Aggressor.

#1: Aggressor is a Canadian thrash metal band formed in Ottawa, Ontario in 2006. Today it consists of Brain Stephenson (Annihilator, Sanctity), Adam Pell, Max Gingras and Chris Stephenson.

#2: Aggressor was formed in Estonia back in 1989. In the beginning of 1990 they "released" their first rehearsal demo "Indestructible" - it had strong influences of Kreator. Their first official gig was on April 17th, 1990. A year later they recorded a 4-track demo and in the end5 of 1992 Aggressor recorded their first MC "Procreate the Petrifications". After that they played several gigs in Moscow, Russia. In 1994 the second album "Of Long Duration Anguish" was released as MC and CD. Corrosia Metalla cover "Russian Vodka" on that album was sang by bassist Cram which resulted in the idea of changing their style. In 1995 Aggressor performed at the biggest rock-festival in Estonia "Rocksummer '95". After that they went into studio (still as Aggressor) where they were suggested a name-change. So in 1996 they wrote lyrics to a song titled "No-Big-Silence 99" (a street in the USA where a massmurder was committed). So the album was titled "99" and band was renamed "No-Big-Silence".

#3: Aggressor is a RAC band from Germany.

#4: Aggressor is thrash metal band from Banja Luka, Bosnia&Herzegovina, formed in 2007,influenced by old school thrash metal bands such as Kreator,Sodom and Destruction.
Band members:
Mladen Dodoš - vocals
Aleksandar Bjelošević - guitar
Nikola Arežina - guitar
Aleksandar Milosavljević - bass
Boris Stanković - drumms.
They have released demo called Eternal Slaughtering through Okkullt Darkness Records.

#5: Aggressor is polish death metal band.

#6. Aggressor is a hardcore band from Melbourne, Australia featuring members of Headcheck and Trainwreck.

#7 Death/Thrash Metal from Spain. Active: 1985-1991 Only had one demo "Brutal Aggression" 1988.

#8 Aggressor is a Thrash Metal band from Cuernavaca, Morelos, Mexico.
Current members are:
Jack Daniel - Guitar, vocals.
Emmanuel "Tata" Bahena - Guitar.
Dexter Martin - Bass.
Luis Álvarez - Drums.
they have released 1 demo and 2 full-length albums. after releasing Bury Your Idols in 2016 they have changed the view of Mexican early thrash metal scene. here is discography:
Release of Aggression - Demo - 2010
Release of Aggression - Full-length - 2013
Bury Your Idols - Full-length - 2016
note that they were working under the name of Mandra from 2008 to 2010 and released an EP named Revolutionary Madness. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.