The Invader is the Scourge's primary armoured personnel carrier, and a common sight amidst Scourge armies. Its approach is greatly feared however, as it invariably precludes the assault of sinister Scourge infantry units. Its large front assault ramp allows its cargo to spill forth from its armoured prow, straight into the fray.
The Invader is an unusual vehicle by Scourge standards, since it's unarmed! However, this is more than compensated for by its considerable carrying capacity - a full squad of 15 Warriors. Given the space taken up by the Anti-Grav drive, it is perhaps unsurprising that there was no room to include a weapon.
Rules for this unit can be found in the Core Rulebook