Vertigo (5e Creature)
From D&D Wiki
Medium monstrosity, lawful evil
Spider Climb. The vertigo can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Web Sense. While in contact with a web, the vertigo knows the exact location of any other creature in contact with the same web.
Web Walker. The vertigo ignores movement restrictions caused by webbing.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 14 (4d6) piercing damage, and the target must make a DC 13 Constitution saving throw, taking 8 (3d4 + 1) poison damage on a failed save, or half as much damage on a successful one. Additionally, on a failed save, the creature is energized as if by the haste spell for 1d2 rounds, after which it gains a level of exhaustion and is paralyzed for twice as many hours.
These creatures are the result of the unnatural fusion between a humanoid and a hunting spider. Despite the fact that they are almost always created and employed as servants by evil magic users, the typical vertigo is a reclusive, cautious, and courteous being. They use their webs and impressive agility for hunting smaller animals such as birds or bats and can easily be convinced to release more intelligent prey unharmed, although if hungry or angered they have no qualms about feeding on humanoids. Troublesome meals are subdued with its neurotoxic venom, known for causing a burst of energetic convulsions or "dancing" before the victim succumbs to a prolonged state of paralysis.