SnailSong OSR Blog

A despicable little maggot from outside reality

Pestiary is a series of posts we’re devoting to magical pests usable in your fantasy OSR games. Many bestiaries focus on the flashy bear+ sized creatures, the goal of Pestiary is to create low HD creatures which can be scattered around your fantasy world to add flavour. Some may present combat challenges, whilst others will offer new ways of interacting with the world.

Description

Mana Leeches should not exist, they are the coalesced energy of arcane hubris given material form. Spawned in the aftermath of magical catastrophes, mana leeches literally hunger for arcane knowledge.

A Mana Leech appears to be a 1′ long, wriggling maggot. It floats through the air under unknown power and emits a sickly blue light from pockmarks across its ridged body. It is blind to mundane senses, but possesses the uncanny ability to sense magic in its surroundings, hungering particularly for the knowledge nestled within the minds of spellcasters.

An individual wearing only mundane equipment and without any spells memorized will find that even a swarm of mana leeches takes no interest in them. However, when they bring their Magic-User or Cleric friend to investigate, the leeches will sense any memorized spells and converge to attack!

Once a Mana Leech reaches a source of magic it will begin to gorge upon it by emitting a ghastly blue cone of energy. Magical items are slowly drained of their power and memorized spells are excruciatingly ripped from the minds of spellcasters. A Mana Leech that has consumed its fill of arcane energy for the time being becomes gorged and writhes around on the ground, fat and happy, until it is ready to fly again.

Mana Leeches can sense memorized spells or magical items within 60′ and move through the shortest possible path to get towards it (preferring spells, but stronger magic takes precedence at GM discretion). This sense extends through solid objects (excepting 1″ of lead or an anti-magic zone/material). Due to their low intelligence, mana leeches are frequently found bouncing off of walls, doors, or cabinets in a futile effort to get to the magic behind. Once the predictability of their pathfinding is observed, a clever individual may be able to exploit it to lure them towards enemy Magic-Users or away from desired treasure.

Mana Leeches do not reproduce naturally, they simply pop into existence around rips in space where magic has gone wrong. This makes infestations easy to manage if the leeches can be destroyed, but if an underlying rip in reality is not addressed they may soon be back.

Realms which forbid or license the practice of magic may use caged mana leeches as a method of detection. The leeches will float around lazily in the presence of mundane individuals, but anyone with memorized spells or magical equipment will set them off instantly.

Mechanics

Mana Leech
1′ long flying maggots, emitting sickly blue light from marks along their bodies.
AC 9[10]
HD 1/2*
THAC0 19[0]
Movement 15′ (5′) / 60′ (20′) flying
Saving Throws D12 W13 P14 B15 S16
Morale 11
Alignment Neutral
XP 6
Number Appearing 2d8
Attacks 1x of the following: Thwack – 1d2 Leech Mana – Target must save against spells or randomly lose one of their lowest level currently memorized spells, taking 1d6 damage per level of the spell lost (usable only against targets with memorized spells). Leech Item – Targets one magic item adjacent to the mana leech. If multiple items are present (such as when worn by an adventurer) choose randomly. There is a 5% chance that the item is drained of some of its magical energy. Draining should generally take the item down one ‘tier’ of efficacy (+2 items becomes +1, +1 items become +0 and so on). When the drained effect is unclear, the GM is encouraged to introduce unreliability or some other quirk to the item’s function over rendering it entirely mundane.
Sickly Glow Mana Leeches passively emit dim blue light in a 10′ radius.