uncommon ce gargantuan aberration aquatic 

Perception +31; blood scent, darkvision, scent (imprecise) 100 feet

Languages Aquan, Common

Skills Athletics +34, Intimidation +30, Survival +31

Str +9 Dex +5 Con +9 Int +0 Wis +6 Cha +5

Blood Scent The lusca can smell blood in the water up to 1 mile away.

AC  40; Fort +32, Ref +26, Will +29

HP 320; Immunities electricity

All-Around Vision

Storm Bringer (aura, evocation, primal) When the lusca is near the surface for more than 1 hour, clouds appear and deliver a thunderstorm with a 2-mile radius centered on its location. The weather returns to normal 1 hour after the lusca departs.

Attack of Opportunity [R] The lusca gains 2 extra reactions at the start of each of its turns that it can use only to make an Attack of Opportunity with its jaws. It can't use more than one Attack of Opportunity triggered by the same action.

Speed 10 feet, swim 50 feet

Melee [>] jaws +35 (magical, reach 20 feet), Damage 3d12+17 piercing plus Grab

Melee [>] tentacle +35 (magical, reach 40 feet), Damage 3d10+17 bludgeoning plus lusca venom

Primal Innate Spells DC 38; 9th chain lightning (×3); 8th punishing winds (×3)

Capsize [>] (attack) The lusca tries to capsize an adjacent aquatic vessel of its size or smaller. It must succeed at an Athletics check with a DC of 35 (reduced by 5 for each size smaller the vessel is than the lusca) or the pilot's Sailing Lore DC, whichever is higher.

Lusca Venom (poison) Saving Throw DC 38 Fortitude; Maximum Duration 6 rounds; Stage 1 4d6 poison damage and clumsy 1 (1 round); Stage 2 6d6 poison damage and clumsy 2 (1 round)

Ravenous Jaws [>>] The lusca makes three jaws Strikes, each against a different target. These attacks count toward the lusca's multiple attack penalty, but the penalty doesn't increase until after the lusca makes all of these attacks. If the lusca subsequently uses the Grab action, it Grabs any number of creatures it hit with Ravenous Jaws.

Rend [>] (jaws)

Swallow Whole [>] (attack) Huge, 4d12+9 bludgeoning, Rupture 38.

AoE5, page 83.