Maybe a 4 square critter with a point of Reach to simulate tentacles of slime grabbing your gear. Spend a surge to "eat" a piece of gear at random, but exclude Runes as valid targets. Canon says that they are etched into the flesh of the caster. Hard to steal that...
Where does it say that? If that was strictly the case, they wouldn't have rune items that can be traded.
I was fairly certain that I read that in the first edition rules somewhere. Is it not the case? I was just going off of the background mythos.
The vast majority of rune spells are carved on stones, per the lore. That's why all the rune items are depicted as an icon on a trapezoidal stone slab. One assumes those icons are not the actual runes, but you get the idea.
There is precedent for some people carving magic runes into their bodies (see the Cult of the Rune adventure variant for Runebound), but that's generally rare. I suppose the Runemaster class has that one skill that allows him to put a rune on any weapon, too. That would presumably be carved/written directly on the weapon.
I can't think of any cases from D1E where someone had runes carved into their body (off the top of my head), unless perhaps it was something mentioned in the description of golems. There were a few cases of that sort of thing in Runebound; if you're familiar with that game, perhaps that's where you read it.
There are no Uthuk Y'llan monsters yet (to my knowledge anyways...)
Nope, there are no Uthuk monsters in Descent yet. There's the Uthuk Demon Trap OL card in D2E, but that's about it. I'd be cool with a big box expansion focusing on the Uthuk as an enemy, personally.
Of course, there's BattleLore 2.0, which has lots of Uthuk units (including Chaos Lords) that I'm told are to scale with Descent figures. So if FFG doesn't introduce them officially, I'm sure there will be tons of homebrew fodder coming from BL.