This is a skill point.
Later into this level, there will be big mutant crabs, these are the enemies that will be led into the force field. You will eventually reach a force field (giant red barrier), where on the other side are sleeping mutant crabs. There is also a Swingshot target above this forcefield. All you need to do is equip the taunter and then use it near the barrier, the crabs will wake up and run towards you, ad the barrier will kill them. The trophy and skill point will unlock shortly afterwards.