Remember when I talked about there being so many fiendish dog variants? Guess what, now there's fiendish lycanthropes!
Canomorphs, like werebeasts, have confusing statblocks that assume the base creature already has some character levels. Unlike lycanthropes, they don't have an easily-summarized template description. I'm going to just be stripping away all class levels (as well as their elite stats) and rate the resulting monster as if it's a standalone creature, which seems like the most consistent way to handle this.
Short sidenote: canomorphs state that their ability scores are basically just the base stats of their beast form with the elite array applied, except that they don't match those stats. Combined with the difficulty of reverse-engineering the elite array, I'll be ignoring the statblock ability scores where and substituting the (nearly equivalent ones) of the 3.0 fiends instead.
Traits shared by all canomorphs are easily summed up: they can use Greater Command against beasts of their kind, get Scent, and of course can shift into a humanoid form (that's right, the canines are their base form) as a move action. This alternate form doesn't affect the things they are carrying or wearing, so either get two sets of armor or focus on one form for combat.
Hell hound variants. They come with four outsider HD, mediocre stats (+2 to all physicals, -4 intelligence and charisma), and a rather weak breath weapon that deals only 1d4+1 fire damage. 40 ft. base movement, +5 natural armor, an 1d8 bite (no fire rider) and Track as a bonus feat. I guess a Small-sized party member can ride you, if that ever ends up being relevant.
Their humanoid form has the general advantages of being humanoid, at the cost of 10 ft. of speed and the bite attack.
Honestly, I can see why 3.5 buffed hell hounds: this is just kind of pathetic. Losing out on four levels isn't good, and net negative stats combined with rather useless secondary abilities isn't either. Hell Hounds had many problems, and being nonhumanoid was only one of those. -0 LA.
Shadow Mastiffs, which actually got +1 LA when I first reviewed them (maybe it should be lowered to +0 though?). 4 outsider HD again, bonuses to all stats (if you ignore the -6 intelligence) ranging from +6 to +2, 50 ft. land speed, an 1d6 bite that Trips, and the ability to enter shadow and get a 40% miss chance (or, by 3.5 rules, total concealment) until you're in real or magical daylight. Shadurakuls can also Bay, which panics all non-evil outsiders within 300 ft. for 2d4 rounds and is pseudo-friendly (use it on your allies and they become immune for the day).
Humanoid form can still bay and shadow blend, but loses the ability to Trip (even if it gains a new bite attack) and slows down by 20 ft.
I think this is worth +0 for sure, perhaps even +1. Shadow Blend is a great ability, and Bay has its uses too. The stats are nice, and the humanoid form helps a lot as well. +0 for now, we'll see if it is worthy of more.
Based on the Vorr from the same book. Only 3 outsider HD, but stats on par with the shadurakul's (+6 strength and dexterity, +4 constitution and charisma, -4 intelligence). Additionally, the vultivor gets 2d6 sneak attack, which synergizes nicely with its 2d4 bite (with Trip) and two 1d3 claws.
On top of that, vorrs also get 160 ft. of Shadow Jumps per day, and can assume a shadow form for ten minutes per day. Said form is... ill-defined, but apparently gives it immunity to most damage (3.0 rules say 'DR 50/+5', 3.5 update booklet is helpfully silent), resistance to acid and fire, immunity to many statuses, and the ability to move across walls, ceilings, and liquids.
Considering that it can also turn humanoid without losing much (Bite, Trip, movement speed), this seems like a straight upgrade from most rogues, especially after it takes a level in rogue for even more sneak attack and Trapfinding. +1 LA for sure, maybe even +2.
Big update this time: if I messed anything up please tell me.