To unlock the Predator trophy in Assassin's Creed III Remastered, you will first need to progress to Sequence 6 of the story when you obtain the rope darts.
When you first get the rope darts, you will only be carrying three, so make sure you go and buy two more to go for the trophy.
To use the rope darts, find a tree somewhere in Boston or New York, stand on a branch and wait for enemies to walk below you. When they do, make sure you have your rope darts selected, press and hold the
button to attack an enemy with the rope dart and then pull back on the
.
Once you have done this to five enemies, the trophy will unlock.