Amphibious. Shanzezim can breathe air and water.
Elemental Demise. If Shanzezim dies, its body disintegrates into a burst of water and foam, leaving behind only equipment the marid was wearing or carrying.
Innate Spellcasting. Shanzezim's innate spellcasting ability is Charisma (spell save DC 16, +8 to hit with spell attacks). It can innately cast the following spells, requiring no material components:
At will: create or destroy water, detect evil and good, detect magic, fog cloud, purify food and drink
1/day each: conjure elemental (water elemental only), control water, gaseous form, invisibility, plane shift
3/day each: tongues, water breathing, water walk
Multiattack. Shanzezim makes two trident attacks.
Trident. Melee or Ranged Weapon Attack: +10 to hit, reach 5 ft. or range 20/60 ft., one target. Hit:13 (2d6 + 6) piercing damage, or 15 (2d8 + 6) piercing damage if used with two hands to make a melee attack.
Water Jet. Shanzezim magically shoots water in a 60-foot line that is 5 feet wide. Each creature in that line must make a DC 16 Dexterity saving throw. On a failure, a target takes 21 (6d6) bludgeoning damage and, if it is Huge or smaller, is pushed up to 20 feet away from the marid and knocked prone. On a success, a target takes half the bludgeoning damage, but is neither pushed nor knocked prone.