The Acromantula is a monstrous eight-eyed spider capable of human speech. Its distinctive features include thick black hair that covered its body; its legspan. which may reach up to fifteen feet; its pincers, which produce a distinctive clicking sound when exited or angry; and a acid secretion. 

The Acromantula's lair in high mountains or forests, dwelling in caverns under snow-capped peaks, or within the tall grasses of thick forests. Caves with moist areas and lots of hiding spots are the most highly prized Acromantula lairs, creating hazards that hinder intruders from seeing them.

Throughout the lair complex, adventurers get caught in webs and poison traps throughout the lair. 

• A tremor shakes the lair in a 60-foot radius around the Acromantula. Each creature other than the spider on the ground in that area must succeed on a DC 15 Dexterity saving throw or be knocked prone.

• Poison gases form a cloud in a 20-foot-radius sphere centered on a point the Acromantula can see within 120 feet of it. The sphere spreads around corners, and its area is lightly obscured. It lasts until initiative count 20 on the next round. Each creature that starts its turn in the cloud must succeed on a DC 13 Constitution saving throw or be poisoned until the end of its turn.

After defeating the Acromantula the lair slowly caves in over time and the tremors and poses gasses stop.