Amphistaff (5e Creature)
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Small monstrosity, unaligned
Power Glands. The amphistaff is resistant to radiant damage and to bludgeoning, piercing, and slashing damage from nonmagical attacks that aren’t adamantine as long as it isn’t incapacitated. In addition, the amphistaff's attacks are treated as adamantine for the purpose of overcoming resistance or immunity to slashing and bludgeoning damage.
Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) piercing damage and 14 (4d6) poison damage.
Tail Lash. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage or slashing damage.
Poison Spit. Ranged Weapon Attack: +4 to hit, range 20/60 ft., one target. Hit: 14 (4d6) poison damage, and the target must succeed on a DC 12 Constitution saving throw or become poisoned for 24 hours. A poisoned creature can repeat the saving throw at the end of each hour, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, that creature is immune to the poison spit of all amphistaffs for 24 hours.
Amphistaffs are poisonous serpents bred by the Yuuzhan Vong for use as living weapons. Their venomous fangs and natural power fields make an amphistaff dangerous at any range.
Bizarre Life Cycle. Amphistaffs grow in trios from a sessile polyp. They serve as the polyp's appendages, coiling around any prey that draws near and dragging it into the polyp’s ravenous mouth. Eventually, the amphistaffs grow too large for the polyp to support them: they break off and slither away into the undergrowth, leaving the polyp to die. In time the amphistaffs will take root and mature into new polyps, producing a new trio of amphistaffs asexually. Until then, they behave much like any other predatory, venomous snake.
Impossible Edge. Amphistaffs have natural "power glands" which project an invisible energy field around its body. This field protects the amphistaff from harm, and also serves as a deadly weapon. By concentrating, the amphistaff can shape the power field in such away that it produces an impossibly keen edge, letting it cut through all but the hardest materials with a simple lash of its tail.
Bond between Weapon and Wielder. Feral amphistaffs are impossible to train, but if a prospective warrior can catch an amphistaff just as it breaks free of its polyp, the amphistaff will imprint on them. It can then be taught to follow simple commands through a combination of language and gestures. The most skilled Yuuzhan Vong warriors wield their amphistaffs like mutable weapons, able to coax them into different forms as necessary during combat. An amphistaff may behave like a quarterstaff one second, only to become pliant like a whip the next. Alternatively, the warrior may hurl his amphistaff like a spear at a distant target or have his amphistaff spit deadly globs of contact poison.