Carrion Crawler Zombie

Keen Smell. The zombie has advantage on Wisdom (Perception) checks that rely on smell.

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

Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damagetaken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Tentacles. Melee Weapon Attack: +4 to hit, reach 10 ft., one creature. Hit: 4 (1d4 + 2) poison damage, and the target must succeed on a DC 14 Constitution saving throw or be poisoned for 1 minute. Until this poison ends, the target is paralyzed.

 The target can repeat the saving throw at the end of each of its turns, ending the poison on itself on a success.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) piercing damage.

Sudden Lunge. If an enemy moves within 15 feet of the zombie, roll a d20. If the roll is 11 or higher, the zombie moves up to 5 feet toward the enemy. If the zombie ends within 10 feet of the target, the zombie can make one attack at it with its tentacles.