This guy is amazing. A 5/5 for 5 is already pretty decent, not to mention he is a Zombie Warrior.
Although, he isn't perfect. He can't stand up unless you sacrifice another creature, *couch* Gravecrawler *cough*, but he does get a +1/+1 counter every time you do this. Oh, also, he pretty much has Annihilator 1, but YOU decide what dies. He also gets +1/+1 counter for this too.

Finally, we have our sacbait. SACBAIT, HOO-HA-HA!
First up, the classic Gravecrawler. He was made to be sent to the slaughter house, then rebuild himself, like those Hippo Tokens that Pheldagriff makes. Oh, hey, tomorrow's review topic just came up.
Another obvious sacbait is anything of your opponents. A good way to get things of your opponent's in Blue/Black is Ashen Powder, or, if you can get ahold of some more Blue or Black allies, Agadeem Occultist.
Well, friends, I'm sorry this was too in depth, but I am new to this, so hopefully they'll get bigger and better.
Also, prices for cards mentioned for this commander review are below.
Grimgrin: http://store.tcgplayer.com/magic/innistrad/grimgrin-corpse-born
Gravecrawler: http://store.tcgplayer.com/magic/dark-ascension/gravecrawler
Midnight Recovery: http://store.tcgplayer.com/magic/gatecrash/midnight-recovery
Rooftop Storm: http://store.tcgplayer.com/magic/innistrad/rooftop-storm
Ashen Powder: http://store.tcgplayer.com/magic/classic-sixth-edition/ashen-powder
Agadeem Occultist: http://store.tcgplayer.com/magic/worldwake/agadeem-occultist