Echolocation. The whale can't use its blindsight while deafened.
Hold Breath. The whale an hold its breath for 30 minutes.
Keen Hearing. The whale has advantage on Perception checks that rely on hearing.
Bash. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8-20-33 5d6+3 Bludgeoning Damage.