Huge Beast, unaligned
Armor Class 12 (natural armor)
Hit Points 90 (12d12+12)
Speed swim +60
Challenge 3
Skills perception +3
Senses blindsight 120 ft., passive Perception 13
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.
Source: 5e Core Rules · OGL/Open