Echolocation. The whale can't use its blindsight while deafened.
Hold Breath. The whale can hold its breath for 30 minutes
Keen Hearing. The whale has advantage on Wisdom (Perception) checks that rely on hearing.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 21 (5d6 + 4) piercing damage.