Stick Around Trophy

The Combi Stick is another weapon used by the Predator. You will know when you have picked it up because it is long like a spear. To use the spear just press & hold to ready the weapon & use the analogue stick to choose the direction you want to throw it in, then just release to throw the weapon. Also the stick seems to fly a bit upwards once thrown so this requires you to aim a lot lower than normal.

The last level on the Predator campaign is very good for this. You will face a small onslaught of aliens on the bridge near the start of the level, simply kill as many as you can until there are no more enemies remaining then just reload the last checkpoint to start back near this fight.