The Brain Sucker is an Irregular mutant that appears in Resident Evil 3: Nemesis. Like the Drain Deimos, these creatures were born from arthropods (most likely fleas) infected by the T-virus. However, it has been suggested that these creatures became infected even before the massive viral outbreak brought about after William Birkin injected himself with the G-virus, having come into contact with contaminated waste at Umbrella's incineration plant.

Brain Suckers have only been spotted at Disposal Plant P-12A, aka the "Dead Factory". They behave in a very similar fashion to Drain Deimos, but they are slightly stronger and capable of spitting poisonous fluids at enemies. The exoskeletons of these deformed creatures are torn in various places, exposing patches of muscle beneath. Most notable is the fact that Brain Suckers each have two heads, each one with two long wiry tongues. These monsters are called "Brain Suckers" because their preferred nourishment appears to be the brains of their victims.