Derro

A small, stocky dwarflike creature in studded leather armor titters and mumbles to himself. His skin is a pale blue-white color, and his bulbous white eyes have no irises or pupils. His hair is coarse and white, and a long mustache droops past his chin.

Derro are degenerate and evil creatures of the underground, created from dwarf and human stock by some nameless deity of darkness and madness. Incredibly cruel and murderously insane, they enjoy taking slaves and torturing surface dwellers (especially humans) to death.

Derro are afflicted by a form of racial madness, which most often manifests as delusions of grandeur coupled with an overpowering urge to inflict torment on other creatures. Derro are capable of holding their murderous impulses in check for short periods of time in order to cooperate with creatures of other races, but such arrangements rarely last more than a few weeks. Of course, no derro is capable of recognizing that he is out of his mind.

Combat

Derro are stealthy and bloodthirsty. They like to carefully arrange cruel traps and deadly ambushes, and strike savagely from hiding. They delight in taking captives who can be tortured to death later, and favor traps and poisons that disable without killing.

Madness (Ex): Derro use their Charisma modifier on Will saves instead of their Wisdom modifier, and have immunity to confusion and insanity effects. A derro cannot be restored to sanity by any means short of a miracle or wish spell.

The racial madness of the derro provides a +6 bonus to their Charisma scores and a –⁠6 penalty to their Wisdom scores. These are accounted for in the statistics block above. A derro restored to sanity gains 6 points of Wisdom and loses 6 points of Charisma.

Poison Use (Ex): Derro typically carry 2d4 doses of greenblood oil or Medium monstrous spider venom (see Poison), applying it to their crossbow bolts. Derro are not at risk of poisoning themselves when handling poison.

Sneak Attack (Ex): Any time a derro’s opponent is denied his Dexterity bonus to AC, or if a derro flanks his opponent, he deals an extra 1d6 points of damage. This ability is just like the rogue’s sneak attack and subject to the same limitations.

Spell-Like Abilities: At will⁠—​darkness, ghost sound; 1/day⁠—​daze (DC 13), sound burst (DC 15). Caster level 3rd. The save DCs are Charisma-based.

Vulnerability to Sunlight (Ex): A derro takes 1 point of Constitution damage for every hour it is exposed to sunlight, and it dies if its Constitution score reaches 0. Lost Constitution points are recovered at the rate of 1 per every 24-hour period spent underground or otherwise sheltered from the sun.

Skills: Derro have a +4 racial bonus on Hide and Move Silently checks.

Derro Characters

Most derro revere Diirinka, a chaotic deity of magic and cruelty. Very few derro are clerics, but those who follow this path can choose two of the following domains: Chaos, Destruction, Evil, or Trickery.

The leaders of the derro are spellcasters called savants, whom other derro follow fanatically. Derro savants are at least 5th-level sorcerers; they have one to three Knowledge skills (usually arcana and other esoteric fields). A savant is accompanied by two lower-level students. Savants use their spells to confuse and frustrate rather than kill, preferring to make slaves of defeated foes.

Source: Monster Manual (version 3.5), page 49.