Where/How to complete the "Cut 'Em No Slack" challenge for Borderlands 2.
Within the Bloodshot Stronghold, head into the area with the four mutants you bring the pizza to during the quest Splinter Group (this can be done during or after Splinter Group). Simply kill the mutants in the order they appear - Lee, Dan, Ralph, Mick.
Disclaimer: Borderlands 2 is a game developed by Gearbox Software, and published by 2K Games - I do not have any affiliation/association with Gearbox or 2K, nor do I claim to have any affiliation/association with them. I do not own, or claim to own, any part of the displayed content - this video is for entertainment purposes only.