Gravislayer (5e Creature)
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Large aberration, neutral evil
Gravsight. The gravislayer has blindsight to 450 feet, but weightless creatures (such as ethereal creatures like ghosts, and gaseous creatures like air elementals) are invisible to it.
Gravity Null. The gravislayer cannot be forced to move, including by falling.
Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 26 (4d10 + 4) piercing damage.
Gravity Nexus. The gravislayer chooses one object, creature or empty space it can see within 450 feet to be a gravity nexus. A gravity nexus becomes "down" for everything within 120 feet of it: thus any non-flying creature or object will fall towards it. When two creatures or objects collide as a result of falling, the smaller of the two takes falling damage (and both take damage if they are the same size). If the larger object is Medium, Small or Tiny, falling damage is 1d4, 1d3 or 1d2 per 10 feet respectively (rather than 1d6).
A gravslayer is a large fleshy sphere with no features other than a blunt-toothed maw. Its surface is pitted and scarred from the rigors of wildspace. It presents a hazard to spelljammers, causing the vessel to suddenly drop out of spelljamming speed due to its gravitational disruption.