Some animals produce toxins in their body as a defense mechanism, poisoning those foolish enough to eat them. Phantom beetles instead produce psychic trauma, amplifying their own instinctive fear of death to pollute the minds of those who take their lives. This psychic assault settles into the brain of its victim, becoming a curse that eats away at its victim's sanity. The victim is haunted by vague hallucinations that lurk at the edge of his perception, suggesting terrible things preparing to attack and kill him, just as he attacked and killed the phantom beetle responsible for the curse.

In most circumstances, phantom beetles are non-aggressive, relying on their reputation to dissuade potential attackers and retreating if threatened. However, phantom beetles get territorial when it comes to their immediate lairs, and will attack if they are perturbed within the confines of the their own nests, usually a single, remote chamber in an underground complex.