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

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

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

Magic Weapons. The Acromantula's weapon attacks are magical.

Multiattack. The Acromantula makes two attacks.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one creature. Hit: 14 (2d8 + 5) piercing damage plus 14 (3d8) poison damage. Additionally, the target must make a DC 17 Constitution saving throw or be paralyzed for one minute. A paralyzed creature can repeat the save at the end of its turn.

Web (Recharge 4–6). Ranged Weapon Attack: +10 to hit, range 50/100 ft., one creature. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 16 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; hp 20; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).