Whale, Baleen (CR 6)

Gargantuan Animal
Alignment: Always neutral
Initiative: +1 (Dex); Senses: blindsight 120 ft., low-light vision, Listen +15*, and Spot +14*

AC: 16 (-4 size, +1 Dex, +9 natural), touch 7, flat-footed 15
Hit Dice: 12d8+78 (132 hp)
Fort +14, Ref +9, Will +5
Speed: Swim 40 ft.
Space: 20 ft./15 ft.
Base Attack +9; Grapple +33
Attack: Tail slap +17 melee
Full Attack: Tail slap +17 melee
Damage: Tail slap 1d8+18
Special Attacks/Actions: -
Abilities: Str 35, Dex 13, Con 22, Int 2, Wis 12, Cha 6
Special Qualities: hold breath
Feats: Alertness; Endurance; Toughness (2)
Skills: Listen +15*, Spot +14*, and Swim +20
Advancement: 13-18 HD (Gargantuan); 19-36 (Colossal)
Climate/Terrain: Warm aquatic
Organization: Solitary
Treasure/Possessions: None

Source: Monster Manual

The statistics presented here describe a plankton-feeding whale between 30 and 60 feet long, such as gray humpback, and right whales.

These massive creatures are surprisingly gentle. If harassed or provoked, they are as likely to flee as they are to retaliate.

Blindsight (Ex): Whales can "see" by emitting high-frequency sounds, inaudible to most other creatures, that allow them to locate objects and creatures within 120 feet. A silence spell negates this and forces the whale to rely on its vision, which is approximately as good as a human's.

Skills: Whales gain a +4 racial bonus to Spot and Listen checks. These bonuses are lost if Blindsight is negated.