A Tyranid Prime is a Warrior grown beyond its kin, singled out by the Hive Mind and reshaped into a battlefield commander. Larger, tougher and keener of mind than an ordinary Warrior, it carries a stronger and clearer connection to the collective will, and around it the swarm moves with heightened precision, as though a fog had lifted from the lesser creatures' senses.
The Prime occupies a middle rung in the swarm's hierarchy of control. Beneath a towering Hive Tyrant it will defer, taking its cues from the greater beast and functioning much as a veteran officer does beneath a general, personally leading a brood of Warriors into the thickest fighting. Left to its own devices, it becomes master of its own portion of the battlefield, directing a strike force with an autonomy that few Tyranid organisms are ever granted.
In close combat a Prime is a horror, its bladed limbs moving with a speed and coordination that ordinary Warriors cannot match, and its very presence stiffens the resolve of every creature around it. To face a swarm led by a Prime is to face one that reacts faster, holds together longer, and presses its attacks with a discipline that betrays the guiding hand of the Hive Mind itself.