Magikarp (5e Creature)
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Small beast, unaligned
Undying. Magikarps refuse to die. If put into any situation spelling death (with the exception of situatuions involving electricity), a magikarp can make a DC 10 Dexterity check if it can. On success, a magikarp somehow avoids death entirely.
Air-Breathing. Magikarp is a water-breather. Somehow, however, it can breath air as though it were water.
Dirty Boi. Magikarp can survive in dirty water as though it were pristine.
Flail. Melee Weapon Attack: +2 to hit, reach 5 ft., one creature. Hit: 1 (1d4 - 2) bludgeoning damage.
Splash. The magikarp flops around. All creatures watching it must make a DC 18 Charisma saving throw or feel bad for it.
Magikarp is the demon spawn of the evil Baphomet set upon by the ancient god of beast servants, Arceus, to punish sinful fishermen. This decision was quickly resented, as it seems unexperienced fishers cannot avoid reeling them in constantly. They are weak, unusable, and frankly, annoying as hell. They also seem to have a will to live, attempting to avoid attacks constantly.