Shapechanger. The werespider can use its action to polymorph into a spider-humanoid hybrid or into a Large giant spider, or back into its true form, which is humanoid. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Paralyzing Venom. If poison damage dealt by the werespider reduces a creature to 0 hit points, the creature is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.

Spider Climb (Spider or Hybrid Form Only). The werespider 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 werespider knows the exact location of any other creature in contact with the same web.

Web Walker (Spider or Hybrid Form Only). The werespider ignores movement restrictions caused by webbing.

Multiattack. In spider form, the werespider makes two bite attacks. In humanoid form, it makes three dagger attacks. In hybrid form, it makes one bite attack and two attacks with its daggers or claws.

Bite (Spider or Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 7 (1d8 + 3) piercing damage, and the target must make a DC 13 Constitution saving throw, taking 13 (3d8) poison damage on a failed save, or half as much damage on a successful one. If the target is a humanoid, it must also succeed on a DC 11 Constitution saving throw or be cursed with werespider lycanthropy.

Claw (Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage, and the target must make a DC 13 Constitution saving throw, taking 9 (2d8) poison damage on a failed save, or half as much damage on a successful one.

Dagger (Humanoid or Hybrid Form Only). Melee or Ranged Weapon Attack: +5 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 5 (1d4 + 3) piercing damage, and the target must make a DC 13 Constitution saving throw, taking 9 (2d8) poison damage on a failed save, or half as much damage on a successful one.

Web (Spider or Hybrid Form Only. Ranged Weapon Attack: +5 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; resistance to slashing and piercing damage from nonmagical attacks that aren't silvered; immunity to bludgeoning, poison, and psychic damage).