Multiattack. Mesmerizing Spiral then 3 Pseudopods and Engulf.

Pseudopod. Melee Weapon Attack: +9 to hit, 15 ft., one target, 16 (2d10+5) bludgeoning damage target is grappled (escape DC 16).

Engulf. Engulfs one Huge or smaller creature grappled by it. Engulfed target is restrained and unable to breathe unless it can breathe water and it must make DC 16 Con save at start of each of the ooze's turns or take 21 (6d6) acid. If ooze moves engulfed target moves with it. Ooze can have 2 Huge or up to 8 Large or smaller creatures engulfed at a time. Engulfed creature or creature within 5 ft. of ooze can take its action to remove engulfed creature from ooze via DC 16 Str check putting engulfed creature in an unoccupied space of its choice within 5 ft. of ooze.

Mesmerizing Spiral. The fish inside it swim rapidly in a hypnotic spiral. Each creature within 20' of it that can see the fish: incapacitated 1 min (DC 16 Wis negates). While incapacitated its speed is reduced to 0. Incapacitated creature can re-save at end of each of its turns success ends effect on itself. If a creature's save is successful or effect ends for it creature is immune to Mesmerizing Spiral of all shoal oozes for the next 24 hrs.