Alien with head plates - not to be understimated

Most Alien life forms don't use their head as a weapon.

there have been plenty of animals that have horns and Antlers for display and ritualistic mating combat but a true offensive weapon that involves the skull? Very few indeed.

The Jah'wi have this trait. An articulated set of plates beginning just above the nostril flares and ending just before the thoracic vertebrae is the only signal that the Ja'Wi head is a formidable weapon. Originally thought to be decorative or defensive in nature these plates are actually diminutive when compared to the underlying skull and cervical vertebrae structure. Thick muscles around the neck and shoulders can compress the skull and neck by 20-25% and thrust forward at almost 35mph, Neolithic Jah'wi would use this strength to move, lift and build their massive inverted pyramids.

There is no evolutionary evidence to suggest they were anything other than the dominate, sentient Species on their planet. They have strong tradition going back eons of fantastic engineering feats for the resources of each age.