Here is the full list of all 50 Fighters Uncaged achievements worth 1,000 gamerscore.
Perform all combos
Win 20 fights against Deadlock in the open league
Defeat all opponents 20 times each
Win 20 fights against Deadlock
Win 20 fights against The Jackal in the open league
Win 20 fights against Jackal
Win 20 fights against Angel Face
Win 20 fights against Angel Face in the open league
Win 20 fights against Gambler in the open league
Win 20 fights against Gambler
Win 20 fights against Piston Joe in the open league
Win 20 fights against Piston Joe
Perform 50 combos
Win 20 fights against One Jab in the open league
Win 20 fights against One Jab
Win 20 fights against Kawharu in the open league
Win 20 fights against Kawharu
Win 20 fights against El Luchador in the open league
Win 150 fights
Win 20 fights against El Luchador
Win 20 fights against Jawbreaker in the open league
Win 20 fights against Jawbreaker
Win 20 fights against Mover in the open league
Win 20 fights against Mover
Perform all super strikes
Win 20 fights against Rider in the open league
Win 20 fights against Rider
Win 20 fights against Ratface in the open league
Win 80 fights within two rounds
Win 20 fights against Ratface
Beat lightweight opponents 30 times
Win 100 fights
Win League 1
Beat mid-weight opponents 30 times
Beat heavyweight opponents 30 times
Win 40 fights within two rounds
Perform a combo
Blind an opponent 20 times
KO your opponent while he's groggy
Win League 2
Win 30 fights
Perform 50 super strikes
Win 20 fights within two rounds
Finish off the fight with a combo
Knock an opponent to the ground
Win League 3
Win 10 fights
Win a round with less than 10% of your life remaining
Beat your own record 3 times against the same opponent
Use a super strike