wReamEntropy is a force in the Looniverse of chaos and mangled disintegration, accelerating the effects of the Second Law of Thermodynamics. It is only kept in check by the force of Drama, which the Writers supply.
Unsurprisingly, this force was originally explained by wReam, and exists as a reflection of his chaotic storytelling style. Unlike many pre-planned universes, the Looniverse came into existence as a product of uncontrolled posting, pitching from idea to idea at the lightest whim; and thus, this force is baked into its very beginnings. Drama and wReamEntropy are closely tied, the two forces both balancing and feeding each other.
However, it is theorized that it may be possible for this force to evolve into wReamEnergy, a creative power that would work to sustain the Looniverse even while keeping it chaotic.