The Brain Sucker's attacks are comparable to its Drain Deimos counterpart, with the addition of releasing a poisonous substance on its prey when in close-range. The Brain Sucker can stand up to attack humans with its claws. It can also crawl on walls, turning combat into a three-dimensional format when in the city.
While a single handgun shot will cause them to fall down, they will quickly stand back up and attack the shooter. It is advised that the player avoid the Brain Sucker due to its poisonous abilities; these creatures can easily jump on prey from behind to begin this attack.