Modron

In Insular Brythonic mythology, specifically Welsh, Modron ("mother goddess") was a daughter of Avalloc, similar to Matrona. She may have been the prototype of Morgan le Fay from Arthurian legend. She was the mother of Mabon.

In the Dungeons & Dragons fantasy role-playing game, modrons are a monster native to Nirvana, the Outer plane of law. Modrons are living creatures that resemble geometric shapes with humanoid limbs. In later (post-Gary Gygax) versions of Dungeons & Dragons, the Plane of Law was renamed from Nirvana to Mechanus and the Modrons were changed into clockwork robot-like creatures. In the planescape campaign setting, one can play as a Rogue Modron, a modron who has left Mechanus and broken his link to the other Modrons.

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