The Drain Deimos are fleas that have mutated due to the effects of the t-Virus. The name combines drain which alludes to how fleas absorb their prey’s blood through siphoning, and “Deimos,” the greek god of terror. These parasites have grown tremendously in size after sucking the blood of zombies. They share some traits with other infected insects such as the “Chimera” which tend to grab hold of their prey and attempt to feed on their blood.
In the demo gameplay, they can be seen inhabiting dark places and can be found latched near the ceiling. You can sense when the Drain Deimos is nearby when saliva drips from the ceiling. These creatures attack by scratching your face with their claws or lunging at you.