Astral 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.

Spellcasting. The astral spider is a 9th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 15, +7 to hit with spell attacks). The astral spider has the following wizard spells prepared:

 Cantrips (at will): fire bolt, prestidigitation, ray of frost

1st level (4 slots): mage armor, magic missile, shield, thunderwave

2nd level (3 slots): acid arrow, detect thoughts, invisibility, mirror image

3rd level (3 slots): thunderstep, counterspell, lightning bolt

4th level (3 slots): blight, dimension door

5th level (1 slots): synaptic static

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 8 (1d8 + 4) piercing damage, and the target must make a DC 12 Constitution saving throw, taking 9 (2d8) poison damage on a failed save, or half as much damage on a successful one. If the poison damage reduces the target to 0 hit points, the target is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.

Web (Recharge 5–6). Ranged Weapon Attack: +7 to hit, range 30/60 ft., one creature. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 13 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; hp 5; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).