Here is the full list of all 12 Assassin's Creed Freedom Cry trophies - there are 9 bronze, 2 silver and 1 gold.
Liberate 500 slaves.
Swim a total of 1 nmi.
Plunder 30 ships.
Perform 5 air assassinations from a swinging rope.
Harpoon a killer whale.
Achieve 100% synchronization
Disarm the Gouverneur and kill him with the branding iron.
Complete all missions
Kill 5 guards at once with a blunderbuss.
Kill a guard ringing a bell.
Board a ship without losing any crew members.
Free your first slave.