The following special rare weapons can be found throughout the game:

Atlas weapons
  BLR Wicked Troll: Pistol; regenerates health 
  AX Savage Chimera: Revolver; fires random elements, 3x 
  Fire/Corrosive/Explosive/Shock element 
  SG1100 Genocide Hydra: Shotgun; high damage and special spread 
  SG340 Genocide Hydra: Shotgun; high damage and special spread 
  CVL25 Fearsome Cyclops: Sniper rifle; high damage and explosive attack, 3x 
  Explosive element 

Dahl weapons
  RF5D Wicked Hornet: Pistol; 2 shot corrosive burst, 2x Corrosive element 
  AX220 U Savage Anaconda: Revolver; very high damage and accuracy 
  BA 100 War Bulldog: Shotgun; large magazine and fast reload 
  CR38 Scoped Raven: Assault rifle; large magazine and five shot burst 
  CR780 U Genocide Raven: Assault rifle; large magazine and five shot burst, 2x 
  Shock element 
  TEK540D Malevolent Wildcat: Assault rifle; large magazine 
  LBD Fearsome Penetrator: Sniper rifle; large magazine and high fire rate, 2x 
  Fire element 

Hyperion weapons
  RF5.W Wicked Invader: Pistol; large scope with continued burst while zoomed 
  TMP2 Vile Reaper: Pistol; massive melee and steals life 
  BA 630.W Fatal Butcher: Shotgun; Five shot burst 
  ZX330.W Fatal Butcher: Shotgun; Five shot burst 
  AR300.W Genocide Destroyer: Assault rifle; Continuous burst while zoomed 
  CR320 Genocide Destroyer: Assault rifle; Continuous burst while zoomed, 3x 
  Shock element 
  RF200.G Malevolent Bitch: SMG; large critical 
  PPZ1270.G Fearsome Executioner: Sniper rifle; large magazine and five shot 
  burst while zoomed 
  LB1170.G Fearsome Executioner: Sniper rifle; large magazine and five shot 
  burst zoomed, 3x Fire element 
  RPG720.W Colossal Nidhogg: Rocket launcher; Fast reload and rains additional 
  rockets 

Jakobs weapons
  RV21 XX Savage Unforgiven: Revolver; large critical but slow fire 
  KLR330 ZZ Savage Unforgiven: Revolver; large critical but slow fire 
  SG1 XX Genocide Striker: Shotgun; tight spread and large critical 
  VRR29 ZZ Fearsome Skullmasher: Sniper rifle; multiple projectiles 
  GGN20 Long Skullmasher: Sniper rifle; multiple projectiles 

Maliwan weapons
  HRD C Wicked Firehawk: Pistol; powerful incendiary attack, 4x Fire element 
  TK4 Wicked Firehawk: Pistol; powerful incendiary attack, 4x Fire element 
  KLR300 B Pestilent Defiler: Pistol; powerful corrosive attack, 4x Corrosive 
  element 
  MAL300 C Pestilent Defiler: Revolver; powerful corrosive attack, 4x Corrosive 
  element 
  SPR630 B Fatal Plague: Shotgun; powerful corrosive attack, 4x Corrosive 
  element 
  TD3 B Combustion Hellfire: SMG; powerful incendiary attack, 4x Fire element 
  DVL350 C Fearsome Volcano: Sniper rifle; powerful incendiary attack, 4x Fire 
  element 
  GGN30 Solid Volcano: Sniper rifle; powerful incendiary attack, 4x Fire element 

SES Munitions weapons
  BLR4 Wicked Gemini: Pistol; large magazine and split shot burst 
  HRD5.2 Wicked Gemini: Pistol; large magazine and split shot burst 
  TMP88 Vile Thanatos: Pistol; large magazine and fast reload 
  TMP88.3 Vile Thanatos: Pistol; large magazine and fast reload 
  TMP88 Vile Thanatos: Pistol; large magazine and fast reload 
  ZPR43 Fatal Crux: Shotgun; large magazine and special explosive pattern, 1-4x 
  Explosive 
  PPZ470.3 Fearsome Orion: Sniper rifle; large magazine and shock projectiles, 
  3x Shock element 
  PPZ7 Fearsome Orion: Sniper rifle; large magazine and shock projectiles, 3x 
  Shock element 

Tediore weapons
  PRO4-A Wicked Predator: Pistol; generates its own ammunition 
  EQ20-B Savage Equalizer: Revolver; generates its own ammunition, 2x Fire 
  element 
  DEF900-B Genocide Defender: Shotgun; generates its own ammunition, 2x Shock 
  element 
  GRD12-A War Guardian: Assault rifle; generates its own ammunition 
  SV4-A Malevolent Savior: SMG; generates its own ammunition 

Torgue weapons
  RF4 Cruel Violator: Pistol; three shot burst 
  ZX1 Friendly Fire: Shotgun; powerful incendiary attack in special pattern, 3x 
  Fire element 
  KKA4 Malevolent Gasher: SMG; high damage and a burst of rounds 
  LB570 Fearsome Cobra: Sniper rifle; powerful explosive attack but slow fire, 
  4x Explosive element 
  RPG21 Colossal Redemption: Rocket launcher, large rocket with big bang 

Vladof weapons
  TK6 Cruel Rebel: Pistol; large magazine and fast reload 
  HRD6/V2 Wicked Rebel: Pistol; large magazine and fast reload 
  TMP2 Stabilized Vengeance: SMG; high accuracy and ignore shields 
  ZX330/V3 Fatal Hammer: Shotgun; large magazine and high damage, 3x Explosive 
  element 
  RWL20/V3 Colossal Mongol: Rocket launcher; spawns a horde of additional 
  rockets