Weapon Title tells you the series of the weapon and what effects it will have. Any weapon with flavor text is unique to that manufacturer. To know what each flavor text means, go here.
For more information on the mechanics of titles, see Title.
Cobra - Burst fire, affects weapon accuracy and recoil
Pounder - Semi-Automatic Fire only (1 click fires 1 shot), generally high damage and accuracy, low fire rate and clip size
Stomper - Small ammo clip, has scope, does good damage, 3 round burst, and lowers bullet velocity
Destroyer - The destructor has come - Unloads the entire magazine when scoped. Hyperion only
Guardian - Hold your ground... Forever - Ammo regeneration. Tediore only
Raven - 2 more bullets make all the difference - Shoots in bursts of 5 rounds instead of 3. Higher stability. Dahl only
Avenger - Uncommon Power - High zoom, +50% critical hit damage, single shot, slow ammo regeneration. High magazine, higher damage, high tech. Tediore only
Serpens - Poison in your veins - Corrosive x3 or x4, serpentine bullets. Large Magazine and High chance to proc. High Accuracy and High Damage. S&S only
Reaper - Slice, Slice - +300% Melee damage. Killing an enemy with this weapon's blade will restore health. High Fire Rate, high Accuracy. Hyperion only
Thanatos - Big Tony Says "Hi" - Extended magazine. S&S only
Vengeance - Vengeance is yours - Chance to bypass shields. Vladof only
Stalker - You can run, but you can't hide. - Bullets ricochet 5 times. slow velocity. Vladof only
Anaconda - Long and Strong - Increased accuracy and damage. Dahl only
Chimera - A beast of many forms - Fire, Lightning, and Poison - Explosive x3 - x4. The bullets themselves deal explosive damage, but have a chance to be another element: incendiary, shock or corrosive. Atlas only
Defiler - Give Sick - Corrosive x4, chance for increased contagion. Maliwan only
Equalizer - Unending Firepower - Ammo regeneration. Tediore only
Anarchy - Fires 4 projectiles for 2 ammo cost, and highly reduced accuracy (In truth they fire 4 projectiles with 2 ammo cost due to Anarchies having the Double accessory, the Prefix itself may be overwritten by a material Prefix)