Balashi (Snow Whale) - Gargantuan Animal with a hypnotic song

My default playland is a campaign that I created years ago - one on oceans of snow, ice and cold with small little islands of violence and tranquility. Most activity happens on these islands - either on top of spires or in gardens that are surrounded by magical pillars. In theory, the way to get to and fro is to travel the oceans of snow. While there are magical flying ships or magic at higher levels, at lower levels a lot of time a big part of the game is getting from those points. These snow whales are always in the background, always a danger, simply because of their size and strength.

Balashi - Snow Whale

N Medium Magical Beast
Init -1 Senses Darkvision 60 ft.; +17 Perception

 DEFENSE
AC 21 touch 9, flat-footed 21 (-1 Dex, +12 natural)
hp 187 hp (15d10+105 con)
Fort +16, Ref +8, Will +5
Resist Water or Cold Spells DR 30

 OFFENSE
Speed Swim 75 ft. (Snow) or 50 ft (Ice)
Melee Tail Slap +25 (4d10+10) or Bite +20 (3d10+8)
Special Attacks Capsize & Song of Peace

 STATISTICS
Str 30, Dex 8, Con 25, Int 10, Wis 11, Cha 15
Base Atk +15 CMB +29 CMD 38
Feats Diehard, Endurance, Great Fortitude, Improved Bull Rush, Improved Initiative, Iron Will, Power Attack, Skill Focus (Perception)
Skills +17 Perception, -10 Stealth, +33 Swim
Languages Balashi

 ECOLOGY
Environment any oceans
Organization solitary, pair, or pod (3–16)
Treasure Half (swallowed)
Advancement 16-25 HD

 SPECIAL ABILITIES

Song of Peace (Will DC 19 or Will DC 25) Long heralded for their wondrous music, what many people fail to realize is their music has the ability to lull people into a sense of peace and relaxation. Those who hear the music are usually lulled into a mild relaxation, but able to act normally. When threatened, the balashi increases the intensity of their songs, those who hear the wondrous music for two rounds or less, must make a DC 19 saving or fall into a semi-comatose sleep, able to take actions to defend themselves but unable to take violent actions against the snow whale. Those who hear the music for more than nine rounds must save vs Will DC 25 or fall into the same stupor. This music has a 500 meter range.

Capsize (Ex) A whale can attempt to capsize a boat or ship by ramming it as a charge attack and making a CMB check. The DC of this check is 25, or the result of the captain's Profession (sailor) check, whichever is higher. For each size category the ship is larger than the whale's size, the whale takes a cumulative –10 penalty on this CMB check..