Magical beast type is nice, 12 HD are less so. Huge size is good to have, but natural weapons are a bit disappointing. Even Sonic Lance fails to properly stack up to Eldritch Blast at these levels.

Ability scores are okay, though 7 intelligence hurts and 20 strength is on the low side for a Huge 12 HD creature. Vulnerability to sonic is only worth mentioning because it's such a rare trait.

Honestly, I can't be convinced these monsters make good characters at ECL 12. Either you're playing them for size and strength, in which case you'd be better off with almost anything else (consider the androsphinx, or the hydra), or you're playing them for Sonic Lance (why tho), in which case you should be a warlock, a blaster wizard, or literally anything else that gets to throw energy damage around.

-0 LA for sure.