Blood Spider

Bloody Empowerment. The Blood Spider's strength varies depending on the creature used to create it. Replace X in the stat block with the nuimber of hit dice of the sacrificed creature. If X is less than 8, the Blood Spider is Small. If X is 8 or higher, the Blood Spider is Medium. Add X/3 to the Blood Spider's AC and X/2 to its Hit Dice.

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.

Bite. Melee Weapon Attack: +X/2 to hit, reach 5 ft., one creature. Hit: 7 ((X/5)d8 + X/3) piercing damage, and the target must make a DC 11 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: +X/2 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 12+X/3 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10+X/3; hp 5*(X/2); vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).