A houndious takes 5 thulecite, 1 deerclops eye, and 1 guardain horn. Negating the thule this item takes an insane amount of effort to get, with the eye coming from deerclops once a year with an additional 20% chance to snag one from klaus, and the guardian horn needing a whole ruins regeneration from fuelweaver to amass more then one. As a result, this makes it the most expensive item in the entire game, at least in my opinion.
I do believe the rarity is okay, but what I'm not alright with is this item's 2 key issues: The fact that you can't move it, and the fact it bursts into thin air when destroyed. This makes it incredibly risky to use without risking 70+ days of effort being vanished due to a single mistake.
A simple solution is making it being able to be deconstructed with a deconstruction staff, returning all of the items used to make it. This means if it's in an unfavorable position, you can simply break it and recraft it without issue. In addition, I don't think it should break into nothing when destroyed. I believe it dropping both the eye and horn without the thule would be more then sufficient to recover the houndious without losing a huge chunk of progress. At worst, it should at least drop the deerclops eye.
Final note, I do wish houndious would be unable to attack each other. While making them drop loot would be enough, it's extremely frustrating accidently attacking a houndious and having nearby ones attacking each other, meaning you lose multiple houndious at once due to a small error.