The size of a house-cat, this is dull grey beetle with feathery antennae seems to be staring in your direction with its dead, black eyes.
Phantom Beetle (CR 1/2) XP 135
N Small vermin Init +0; Senses low-light vision; Perception +0
--- AC 12, touch 11, flat-footed 12 (+1 natural, +1 size) hp 2 (1d8–2) Fort +0, Ref +0, Will +0 Immune mind-affecting effects Weakness fragile
--- Speed 30 ft., fly 30 ft. (poor) Melee bite +1 (1d4) Special Attacks death curse
--- Str 10, Dex 11, Con 7, Int —, Wis 10, Cha 11 Base Atk +0; CMB –1; CMD 9 (17 vs. trip) Skills Fly –2 SQ luminescence
--- Environment any land or underground Organization solitary, cluster (2–6) or colony (7–12) Treasure none
--- Death Curse (Su) When a creature slays a phantom beetle, the slayer is affected by the curse of nerves. Curse of Nerves: save Will DC 10; onset 1 day; frequency1/day; effect 1d2 Wisdom and creature suffers fleeting hallucinations that cause it to to become shaken for the next 24 hours unless it is immune to fear; Cure —. The save is Charisma-based. Fragile (Ex) A phantom beetle dies if reduced to –5 or fewer hit points.
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.