Here is the full list of all 13 Secret Ponchos (EU) trophies - there are 10 bronze, 2 silver and 1 gold.
Reached "Death Bringer" status with 5 outlaws
Ended an outlaw's 10+ winning streak
Defeated an Outlaw in 1 vs 1 Ranked Deathmatch
Won 100 matches
Defeated a Death Bringer in 1 vs 1 Ranked Deathmatch
Achieved "Death Bringer" reputation with an outlaw
Played 50 competitive matches
No damage taken in 10 1 vs 1 matches
Came first in Free For All 5 times
10 match win streak
Achieved a win/loss ratio of 2 (Outlaw or Higher)
Achieved "Outlaw" reputation with an outlaw
Achieved "Bandit" reputation with an outlaw