Borderlands: Game of the Year Edition
81 Achievements
64-76h
Facemelter
Killed 25 enemies with corrosive weapons
36.5%
How to unlock the Facemelter achievement in Borderlands: Game of the Year Edition - Definitive Guide
These weapons have a green hazardous chemical/materials (HAZMAT) sign in the inventory menu.
Green numbers will come off enemies if they are impacted by corrosion. Corrosive damage is like other elemental damage in the game in this is causes damage over time. The enemy does not have to die as a result of the elemental damage however.
You can check your corrosive kill count in the challenge menu, go to the quest screen and press Y.
You can also use barrels for this achievement. Corrosive barrels are green.
Corrosive weapons can be identified by the green hazardous chemical symbol in your inventory (similar to the trophy art image). You can also do corrosive damage by shooting the green barrels.
When you use a corrosive weapon, green numbers will appear around an enemy to indicate that you are causing corrosive damage.
Simply kill 25 enemies with a corrosive weapon. See "Master Exploder" for more details.
You won't start getting corrosive weapons until you level up to approx level 14 and can be recognised by the Green Biohazard symbol on the bottom right of the item description. Corrosive weapons are great against flesh and armour but hopeless against shields. Skags and Spiderants are the best things to kill as corrosive ammo eats right through them. Environmental damage from the Green Barrels that are scattered throughout the game also count towards this trophy. A great place to get this is in the Tetanus Warren as it is crawling with Spiderants.
For a kill to count as an elemental kill, the enemy has to die from the continuous damage which that particular element causes after hitting an enemy, not the normal non-elemental damage (credit to Tostigroover for this info). All elemental weapons have a chance of doing continuous damage to a target after shooting them. The higher the number on the elemental symbol (the maximum is x4), the higher the chance elemental damage will persist.
Unless you go out of your way to avoid corrosive weapons/barrels, this trophy is impossible to miss.