1. Be a howler.
2. Take levels in psychic warrior.
3. Manifest an augmented Compression to shrink by two sizes.
4. Put on a Ring of Reduction.
5. You are now a pandemonium chihuahua.
Oh right, the LA. First of all, howlers have 6 outsider HD, as well as the [Chaotic] and [Evil] subtypes (which makes them one of the weirder FoP entries). At 60 feet, their speed is considerable, and their physical stats are pretty good.
Howlers have two special abilities: their quills, and their maddening howl. The howling is flavorful but incredibly unlikely to influence play, whereas the quills are mostly weird for adding a variable number of natural attacks per round. The slight debuff accompanying quill hits is interesting, though it's a bit unclear what action it takes to remove them (I'm assuming standard, but it's not stated anywhere).
Considering all of this, I think howlers are fine at +0, maybe even -0. They provide people with a fine chassis, but are hampered by a lack of hands and optimizable special abilities. +0 for now, and we'll see what the forum thinks.