Crocodile Zombie

Noxious Bile:   As a bonus action, the Crocodile Zombie can unleash a cloud of poisonous, brackish water in a 5 foot radius of its head that spreads around corners which dissipates at the beginning of its next turn. When a creature is enveloped for the first time on a turn or starts its turn in the poisonous water, that creature must make a Constitution saving throw. The creature takes 5d8 poison damage on a failed save, or half as much damage on a successful one. Recharge: (4-6)

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

Crocodile Speed: The Crocodile can reach 10 feet in its bite attack using a burst of speed and then shuffling away into its starting position while dragging a grappled target along without provoking attacks of opportunity. This can only be done on land. 

Multiattack. The crocodile makes two attacks: one with its bite and one with its tail.

Bite. Melee Weapon Attack: +8 to hit, reach 5 (10) ft., one creature. Hit: 7 (1d10 + 5) piercing damage, and the target is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the crocodile can't bite another target.

The crocodile can "Death Roll" a grappled target instead of other attacks if in water. The crocodile rolls over and over with the captured prey who suffers 16(2d10 + 5) and is incapacitated until the beginning of the crocodiles next turn due to disorientation unless it succeeds on a DC 16 Wisdom saving throw  

Tail. Melee Weapon Attack: +8 to hit, reach 10 ft., one target not grappled by the crocodile. Hit: 14 (2d8 + 5) bludgeoning damage. If the target is a creature, it must succeed on a DC 16 Strength saving throw or be knocked prone