Shapechanger. The werespider can use its action to polymorph into a spider-humanoid hybrid or into a Medium 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 Poison (Spider or Hybrid Form Only). If the werespider succeeds in biting its opponent the poison that it delivers will cause its opponent to become paralyzed on a failed save.

Sight of the Multi-Eyed. The werespider has advantage on Wisdom (Perception) checks that rely on sight.

Spider Climb. 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. The werespider ignores movement restrictions caused by webbing.

Multiattack (Humanoid or Hybrid Form Only). In humanoid form, the werespider makes two scimitar attacks or two longbow attacks. In hybrid form, it can attack like a humanoid or make one scimitar attack and one bite attack.

Bite (Spider or Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (1d10 + 3) piercing damage. If the target is a humanoid, it must succeed on a DC 13 Constitution saving throw or be poisoned taking 18 (4d8) poison damage on a failed save, or half as much damage on a successful one. In addition, on a failed save the target is paralyzed for 1 hour.

Scimitar (Humanoid or Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage.

Sting (Spider or Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 2 piercing damage. If the target is a humanoid, it must succeed on a DC 13 Constitution saving throw or be cursed with werespider lycanthropy.

Longbow (Humanoid or Hybrid Form Only). Ranged Weapon Attack: +4 to hit, range 150/600 ft., one target. Hit: 6 (1d8 + 2) piercing damage.

Web (Recharge 5–6). Ranged Weapon Attack: +6 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).