Here is the full list of all 26 Rustler trophies - there are 6 bronze, 14 silver, 5 gold and 1 platinum.
Get every trophy.
Complete the first quest.
Catch all horses for This Neigh Land.
Complete all quests for the Loan Shark.
Complete all quests for the Priest.
Complete all quests for the Knights of the Holy Grail.
Complete all quests for the Spanish Inquisition.
Complete the main story line.
Collect 5000 gold pieces.
Wield all weapons available in the game at least once.
Gain and then remove a maximum Wanted rating without dying and with no quest active.
Survive for 5 minutes at maximum Wanted rating.
Kill an NPC with a cow.
Set the amount of blood particles in settings to x5 and kill an NPC.
Plow the fields 10 times.
Kill 5 NPC in 5 seconds.
Block 10 attacks in 60 seconds.
Come first in 10 races.
Collect 20 bodies during the body collecting side activity.
Collect 20000 gold pieces.
Win 10 fights in the MMA side activity.
Collect all horseshoes.
Kill 500 people.
Herd a total of 50 NPCs to mass during the church herding side activity.
Use Pimp-A-Horse 20 times.
Complete 100% of the game, including all quests, side activities, and obtaining every other non-platinum trophy.