Multiattack

The hongaek makes two attacks with its vaporous tentacles.

Vaporous Tentacle

Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 18 (4d8) poison damage, and the target must succeed on a DC 14 Constitution saving throw or be poisoned for 1 minute. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Invisibility

The hongaek magically turns invisible until it attacks or casts a spell, or until its concentration ends (as if concentrating on a spell). Any equipment the hongaek wears or carries is invisible with it.