Keen Smell. The carrion crawler queen has advantage on Wisdom (Perception) checks that rely on smell.
Spider Climb. The carrion crawler queen can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Multiattack. The carrion crawler makes two attacks: one with its tentacles and one with its bite.
Tentacles. Melee Weapon Attack: +10 to hit, reach 10 ft., one creature. Hit: 7 (2d4 + 2) poison damage, and the target must succeed on a DC 15 Constitution saving throw or be poisoned. While poisoned, the target is paralyzed. The target can repeat the saving throw at the end of each of its turns, ending the paralysis effect of the poison on itself on a success. Also while poisoned, the target continues to lose 1 hit point each hour until they consume alchemical antitoxin. Healing through magical means, such as cure wounds or lesser restoration, allows the target to regain hit points as normal but does not end the poisoned condition and continued loss of hit points.
Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (2d8 + 2) piercing damage.