Idea that spent a long time brewing, inspired by jousting knights at a renaissance fair. I had a chance to spend time developing the Jouster alien/Iaculis Diabolis for a BIO class assignment. The creature I ended up submitting wasn't entirely what I had in mind though, it still looked too earthly for my tastes. So I've redesigned it with more arthropod elements.
The Iaculis Diabolis (Iaculis referring to a thrower of spears or javelins) kills prey by running them through with the long lance-like protrusion attached to its cranium. Similar in a way to some fishing birds. It's neck is kept coiled up and can be launched with great force and blinding speed. It hunts prey small enough to lift from the ground, so it can casually pluck the meat from its lance like a shish kebab. The leftovers from a meal are liquefied away by the stomach acids that seep from the pores in the lance. This transforms the remains into a smoothie that can be drained into the Jouster's draw-string hole of a mouth.
The Jouster is fast, and though it occasionally launches surprise attacks from the brush, it can more typically be seen running prey down across the great extraterrestrial plains in which it lives.