This isn't designed as a sneak peek at Razor Coast, because there is much cooler stuff in Razor Coast, but this happens to be something that I needed to create for it, and, you know, I needed a blog entry, so here it is.
Bale sharks were apparently some sort of Pathfinder template, either an official one or one that was created for the Pathfinder version of Razor Coast. When the manuscript got to me for conversion, Skeeter Green had already turned the template special-sharks into regular big (7HD) sharks. However, he'd left the "bale shark" name in there, since we've been keeping some of the Pathfinder names as good flavoring for the slumgullion.
Anyway, I decided that if we've got a good name like "bale shark," we should do something with it. So without really making any major alterations or giant leaps in the monster department, I used my conception of worgs (evil spirit-things in wolf shape) to create a similar type of spirit-in-shark creature, a worg of the seas. Could have called it a warg-shark, I guess, but I think "bale shark" just sounds better.
Hit Dice: 7
Armor Class: 6 
Attacks: 1 bite (1d8+4)
Saving Throw: 9
Special: Feeding frenzy
Move: 0 (swim 24)
Number Encountered: 1 or 1d4+1
Challenge Level/XP: 8/800
In the deeps of the oceans, bale sharks are to normal sharks as wargs are to wolves. They have a malign intelligence that might almost be the presence of a possessing spirit. They kill more than they devour, they ally themselves with powerful leaders of Chaos in the undersea realms, and they will serve as mounts to aquatic raiders and reavers.
Other than their evident intelligence and strangely mottled markings, bale sharks are not physically different from an unusually large, but normal, shark. Since other sharks tend to roam in the same area, however, a bale shark attack may trigger the approach of other sharks, and a feeding frenzy. The feeding frenzy operates as per normal, although the bale sharks are able to control themselves.
A feeding frenzy will cause 2d6 sharks of any size to appear from surrounding waters. All the shark will attack madly, and each time a shark attacks there is actually a 1 in 6 chance that it will target another shark instead of a human.
*the art I used for this is the awesome work of Dan Mumford. I had to track down that link, by the way, because the original image linked to a dead myspace page. Plus, I claim dibs on finding him as an artist; he's awesome.