Manaplasm

Shapeless and boneless, the manaplasm hunts with the silence of a cat. It feeds on magic, particularly enchanted items and weapons.Dungeon Fantasy Monsters 2, p.26 As such, it's the bane of wizards and adventuring parties, not causing injury but great inconvenience. Some people say the manaplasm is a rectifier of sorts, sent by gods of magic to hunt down greedy munchkins.
== Binding a Plasm ==
Manaplasms can climb walls (slowly, but reliably), but have a limitation on how flat they can squash themselves. They can't slip under doors like slipper oozes, nor batter them down like muscular puddings, so a manaplasm can be kept in place with a mundane barricade of planks. You can still use magic to set up a barricade (such as Shape Earth and Shape Plant) as long as it's fully stable by the time the plasm arrives.
== Proposal: Deeper and Higher Magics ==
If your game has magic in tiers, it may be possible to hit or bind manaplasms with magics that are simply more fundamental than the manaplasm can digest. 
Magic that's incredibly old (archaic), complex (ritual), fundamental (entrusted by spirits of the area), or celestial (divine magics and intervention), may be strong enough to resist a manaplasm's effects. 
Likewise, perhaps a manaplasm is damaged more directly by weapons that are also magic-diffusing.
== You Are What You Eat ==
Manaplasms would make an excellent pet for an enchanter who needs to practice their magic on the same item over and over again, but manaplasms tend to grow in unexpected ways. Wizard colleges often have rumors of manaplasms that were used to de-enchant items until they grew too clever to be kept as pets, and were eventually banished into the basements and tunnels beneath the campus. 
In some variations of this tale, the headmaster (or other faculty member) tried to destroy a cursed artifact by feeding it to a manaplasm, but the manaplasm itself became malicious and intelligent, and it was easier to banish it than have it destroyed, risking the magic escaping to somewhere else.
== Lead-Lined Slimes ==
Manaplasms not only absorb magic, they also effectively block "line of sight" of magic spells. If a magic item is placed within a sturdy box, and that box is placed in a manaplasm, that item will become undetectable by scrying or other detection magic.Dungeon Fantasy Monsters 2, p.27 Legends tell of manaplasms who carry any manner of artifacts in containers--jewelry boxes, djinn lamps, ancient brass vessels with a sigil on the top...
== References ==
* Dungeon Fantasy Monsters 2, p.26-27 
** (the one with the dark cover, not the Goo one!)
Category:Dungeon Fantasy
Category:Monsters
Category:Slime