Pounce. If the acromantula successfully knocks a target prone with a Deadly Leap attack, the acromantula can use the Frightful Presence or Web action as a bonus action.

Soft Underbelly. The Spell Resistant trait does not apply to spells that hit the underside of the acromantula.

Spell Resistant. Any time the acromantula is targeted by a spell that requires a ranged attack roll, the acromantula is unaffected.

Spider Climb. The acromantula can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Standing Leap. The acromantula's long jump is up to 30 feet and its high jump is up to 15 feet, with or without a running start.

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.

Deadly Leap. If the acromantula jumps at least 15 feet as part of its movement, it can then use this action to land on its feet in a space that contains one or more other creatures. Each of those creatures must succeed on a DC 15 Strength or Dexterity saving throw (target's choice) or be knocked prone and take 39 (10d6 + 4) bludgeoning damage. On a successful save, the creature takes only half the damage, isn't knocked prone, and is pushed 5 feet out of the acromantula's space into an unoccupied space of the creature's choice. If no unoccupied space is with in range, the creature instead falls prone in the acromantula's space.

Frightful Presence (Recharge 6). Each creature of the acromantula's choice that is within 60 feet and aware of it must succeed on a DC 13 Wisdom saving throw or become Frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the acromantula's Frightful Presence for the next 24 hours.

Lunging Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 17 (3d8+4) piercing damage plus 18 (4d8) poison damage. The target must make a DC 14 Constitution saving throw, taking the 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 will make death saving throws as usual and remain poisoned for 1 hour, even after regaining hit points. It is paralyzed while poisoned in this way.

Web (Recharge 5-6). Melee Weapon Attack: +7 to hit, reach 5 ft, one prone target. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 15 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).