Full list of all 12 BloodBath achievements worth 1,000 gamerscore. It takes around 10-12 hours to unlock all of the achievements on Xbox 360.
Reach PITDOG Rank 25
Reach PITDOG Rank 20
Reach PITDOG Rank 15
Reach PITDOG Rank 10
Perform 10 Takedowns
Get 100 kills
Perform 10 Power Hits
Win a Domination match
Win a BloodBath match
Reach PITDOG Rank 5
Win a The Wagon match
Win a Judgement match