This challenge has you killing Varkids. It doesn't matter which ones you kill, but Larva Varkids are definitely the easiest. These can be found in a lot of places and if you do all of the missions, you'll most likely get this challenge done, as long as you don't run past them all. One of the best places to work on this challenge is in Caustic Caverns, as they are in the first area, plus the Infected Warehouse area is full of them.
- Rank 1: Kill 10 Varkids
- Rank 2: Kill 25 Varkids
- Rank 3: Kill 75 Varkids
- Rank 4: Kill 150 Varkids
- Rank 5: Kill 300 Varkids
