Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Echolocation. The whale can't use its blindsight while deafened.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 21 (3d12 + 4) bludgeoning damage

Tail. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 26 (3d12 + 7) bludgeoning damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be pushed up to 10 feet away from the Whale and knocked prone.