Crystallized Giant Spider

Spider Climb. The spider 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 spider knows the exact location of any other creature in contact with the same web.

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

Magic Resistance. The swarm has advantage on saving throws against spells and other magical effects.

Crystalline Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 4 piercing damage, and the target must succeed on a DC 13 Constitution saving throw or the bite Causes light petrifying in the form of crystals to the wounded area lasting for 2 hours

Web (Recharge 4-6). Ranged Weapon Attack: +1 to hit, range 30/60 ft., one creature. Hit: The target is restrained by webbing and must make succeed on a DC 12 Constitution saving throw or be petrified. Any creature that begins its turn in contact with the web, must also make this saving throw or be petrified. As an action, the restrained target can make a DC 11 Strength check, bursting the webbing on a success.The webbing can also be attacked and destroyed (AC 10; hp 15; immunity to fire, bludgeoning, poison, and psychic damage).

Shatter. Upon death, the crystals explode outward within 15 ft. All within range must make a DC 12 Dexterity saving throw or take 4 (3d6) piercing damage.

Lightning Charge. Whenever the spider is subjected to lightning damage, it takes no damage and instead has all its attacks now do lightning damage for 1 hour.