Alphalisk

Petrifying Gaze. If any creature starts its turn within 60 feet of the Alphalisk and the two of them can see eachother, the Alphalisk can force the creature to  make a DC 12 constitution saving throw if the Alphalisk isn't incapacitated. On a failed save, the creature magically begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure the creature is petrified until freed by the Greater Restoration spell, or other magic.

A creature that isn't surprised can avert its eyes to avoid the saving throw at the start of its turn. If it does so it can't see the Alphalisk until the start of its next turn, where it can avert its eyes again.

If it looks at the Alphalisk in the meantime, it must immediately make the save.

Shadow Slink. If the Alphalisk fails to force any creature to make a saving throw with its Petrifying Gaze ability, it can expend a bonus action to melt into the shadows. This allows it to move with twice its movement speed for this turn, and gives it a +5 advantage to stealth rolls.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) piercing damage plus 7 (2d6) poison damage.