Asperim (from the Latin asper-rough, bitter, harsh, particularly in the sense of exasperation)
FREQUENCY: Very Rare
NO. APPEARING: 1
ARMOR CLASS: 6
MOVE: 8”
HIT DICE: 10
% IN LAIR: 50%
TREASURE TYPE: U (no gems or jewelry)
NO. OF ATTACKS: 0
DAMAGE/ATTACK: 0
SPECIAL ATTACKS: Magic only
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: 50%
INTELLIGENCE: Exceptional
ALIGNMENT: Lawful Evil
S I Z E : S
PSIONIC ABILITY: Nil
Exasperation is the key word to describe the Asperim personality. The Asperim are a sort of super-imps. They take delight in annoying any creature near them, in frustrating others and torturing them mentally. They are not actively evil; whatever physical harm they do is usually accidental.
The Asperim are lesser devils who may be found in the outermost circles of Hell. Occasionally they break out to work their deviltry on other planes. The Asperim are 13 in number. They are solitary creatures, since not even another Asperim will willingly subject itself to the company of one of its kind.
The Asperim appear as squat, green humanoids with long, pointed ears. They look something like a cross between a dwarf and a giant frog. The Asperim have a particularly bizarre sense of humor, delighting in crude practical jokes and malicious pranks. They often speak in cryptic exclamations such as: “Aw, go peddle your papers!” or “Your mother wears army boots!”
The Asperim, if asked for information, will always direct the party along the worst possible path. They will not give the same answer twice in a row to the same question. The Asperim have all the spells normal to devils except Fear (since they do not want victims to run in panic). In addition, the Asperim have the following spells: Erase, Nystul’s Magic Aura, Shocking Grasp, Ventriloquism, Audible Glamer, Fools Gold, Forget, Invisibility, Mirror Image, Stinking Cloud, Dispel Magic, Explosive Runes, Slow, Confusion, Fumble, Polymorph Other, Feeblemind, Transmute Rock to Mud, Reverse Gravity, and Otto’s Irresistible Dance. All spells are cast as a l0th-level Magic-User.
The Asperim have no physical or psionic attacks and will teleport away if they cannot harm the party. The Asperim are highly magical in nature and are rumored to be powered by the souls of practical jokers. Asperim have a 70% chance of gating in 1-3 Imps, the only creatures who can stand to be in the company of the Asperim for any length of time.
Originally appeared in Dragon Magazine #42 (1980).
Here's the regular imp:
Devil :: d20srd.org
Note that the Fiend Folio added the Filth, Euphoric, and Bloodbag Imps, all of which might help define this.