Multiattack

Four Bites or Slams; or three Chained Anchors.

Bite (Whale Form Only)

Melee Weapon Attack: +11 to hit, 5 ft., one target, 23 (5d6+6) piercing damage.

Chained Anchor (Giant or Hybrid Form Only)

Melee or Ranged Weapon Attack: +11 to hit 15 ft. or range 30/60' one target 28 (5d8+6) bludgeoning damage and anchor hooks around target. While hooked target and hvalfiskr can't move over 60' apart. Creature including target can use action to detach anchor via DC 19 Str check. Or chain can be attacked (AC 18; hp 50; vulnerability to thunder; immunity to piercing poison and psychic) dislodging anchor into unoccupied space within 5 ft. of target and preventing Reel Anchor.

Slam

Melee Weapon Attack: +11 to hit, 10 ft., one target, 24 (4d8+6) bludgeoning damage.

Whale Song (Recharge 5-6)

Sings magical melody. Each hostile creature within 60' of it that can hear the song: 45 (10d8) psychic and charmed 1 min (DC 17 Wis half not charmed). Charmed creature can re-save at end of each of its turns success ends effect on itself. If creature fails save by 5+ it also suffers short-term madness.