Sources
CR
Type
Size
Alignment
Movement

Whymsee

Medium Humanoid (human), Neutral Evil

Armor Class 17 (natural armor)
Hit Points 75 (10d8 + 30)
Speed 30 ft., swim 30 ft.
STR
12
+1
DEX
10
+0
CON
16
+3
INT
10
+0
WIS
15
+2
CHA
14
+2
Skills Perception +5
Damage Resistances bludgeoning, piercing, slashing, from nonmagical attacks
Senses passive Perception 15
Languages Common, Aquan
Challenge 5 (1,800 XP)

Traits

Amphibious. Whymsee can breathe air and water.

Spellcasting

Innate Spellcasting. Whymsee's spellcasting ability is Wisdom (spell save DC 13, +5 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: command, create or destroy water

1/day each: call lightning, Evard's black tentacles

3/day each: control water, darkness, water breathing, water walk

Actions

Thunderous Touch. Melee Spell Attack: +5 to hit, reach 5 ft., one creature. Hit:27 (5d10) thunder damage.

Ink Cloud. While underwater, Whymsee can expel an ink cloud in a 20-foot radius. The cloud spreads around corners, and that area is heavily obscured to creatures other than kraken priests or a kraken. Each creature other than a kraken priest or a kraken that ends its turn there must succeed on a DC 14 Constitution saving throw, taking 9 (2d8) poison damage on a failed save, or half as much damage on a successful one. A strong current disperses the cloud, which otherwise disappears at the end of Whymsee's next turn.

Shell Defense. Whymsee withdraws into her shell. Until she emerges, she gains a +4 bonus to AC and has advantage on Strength and Constitution saving throws. While in her shell, Whymsee is prone, her speed is 0 and can't increase, she has disadvantage on Dexterity saving throws, it can't take reactions, and the only action she can take is a bonus action to emerge.