Just informing people that I likely will be unable to post as much in the next few weeks. Bear with me, please.
Anyway, the remorhaz, a 7 RHD magical beast with good strength and constitution, okay dexterity, wisdom and charisma, and bad intelligence.
A burrow speed and tremorsense are nice, as is high natural armor, and Improved Grab and Swallow Whole are expected, if not entirely optimal, parts of the creature.
The centerpiece of every remorhaz build will probably be Heat, though. 8d6 damage isn't shabby. Anything with natural weapons is going to take massive damage from even a single full attack, and the same goes for beings attacking with unarmed strikes.
However, there are some factors that negatively influence LA here. Not only is a Heat a good way to destroy any magical weaponry your opponents may be using, it also makes using equipment nearly impossible unless you fireproof it and arguably doesn't even apply to your own attacks. This makes remorhazes very difficult to advance, as past some point any melee role (and with 7 RHD, you're not doing anything else) will simply need to get a lot of magic stuff to remain functional. One might in fact argue that at ECL 7 that point has already been reached.
Next is the roc, better known as the most hilarious technically-lycanthrope-valid form ever.