Is that...a tail?
I guess it's armor in the sense that, yes, there's a layer of something between you and the outside world, it just so happens that layer smells and tastes delicious to any m eat-eating animal. So basically it's bait armor -- half protection, half attraction. Like donning all-black ninja gear to infiltrate an enemy's castle, then setting yourself on fire a mile from the gate.
Thanks to Tam, who has money riding on whatever wild Pokemon appears to fight this guy. Any of them -- including Snorlax mid-nap.