Crystal Spider

Crystalline Camouflage. while the spider is in its natural habitat it has advantage on stealth checks.

Spider Climb. The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Web Walker. The spider ignores movement restrictions caused by webbing.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 4 (1d8 + 2) piercing damage, and the target must make a DC 11 Constitution saving throw, taking  (2d6) necrotic damage on a failed save, or half as much damage on a successful one. If the necrotic damage reduces the target to 0 hit points, the target is stable but paralyzed for 1 hour in a statue of crystal.