When that spell or ability resolves, Hullbreaker Horror won't be countered, but any additional effects of the countering spell or ability will still happen
Well, Lorwyn did establish the type of creature that gets stolen often: Goats
There are likely to be many other surprises and special cards that well all obsess over
(2015-08-25) Gaining control of a creature doesnt cause you to gain control of any Auras or Equipment attached to it
(Bombs, Removal, Evasion, and then Aggro/Defense, or whatever A
Just getting important cards in the graveyard cheaply and reliably would be valuable enough, but those Crabs can do a reasonable job defending you