I've seen severed groins of zombies. I don't believe they can be severed normally (as like destroying the torso, it simply kills the creature leaving a corpse) but I think that it's possible for them to be left in the rotted pile of body parts left behind when a zombie rots to death. It's probably pretty damn rare since the groin is probably more likely to rot away than the torso.
A mystic dark frog? Either that was really a chameleon in disguise, or you had some insane HP. Monster spawns are tied greatly to your max HP (and general power level, though everything else seems to have a minimal effect).
It doesn't even matter if something provides 0 AV, it's still better than nothing. It won't stop direct damage, but fluids will splash on the item rather than you, which can save you from accidental acid spills. Also cloaks are possibly the single most useful piece of armor in the game, since their AV bonus applies to every body part.
Shoutbox search seems to not function, instead returning
Quote
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE shout_message LIKE '%-foo-%'' at line 1"