3 tentacle attacks at +9 to hit dealing 1d6 each attack. If all 3 attacks hit the target must make a DC 15 constitution saving throw. On a failure its speed is halved, it has disadvantage on dexterity saving throws and it can't use reactions for 1 minute. Moreover, on each of its turns, it can take either an action or bonus action, but not both. At the end of each of it's turns, it can repeat the saving throw, ending the effect of itself on a success.