I've recently worked a bit on this casual deck. It runs quite nice I must say, even if it dies with no hope against big graveyard hate, and has no hope against combo. But against all other decks is really nice, and what's more important for a casual deck, really amusing. However, since power is always nice too, I am asking about some tips.
Let's start with the decklist, and then some comments:
// Mana (22+lotus+4rituals)
4 Badlands
4 Wasteland
1 Strip Mine
2 Swamp
2 Bloodstained Mire
2 Polluted Delta
1 Library of Alexandria
1 Mox Ruby
1 Mox Pearl
1 Mox Jet
1 Mox Emerald
1 Mox Sapphire
1 Sol Ring
1 Black Lotus
4 Dark Ritual
// Main Engines
4 Bazaar of Baghdad
4 Skullclamp
4 Zombie Infestation
// Creatures
1 Anger
4 Ashen Ghoul
4 Krovikan Horror
4 Nether Shadow
4 Squee, Goblin Nabob
1 Nim Devourer
// Tutors
1 Entomb
1 Vampiric Tutor
1 Demonic Tutor
The deck works very well if it can use a bazaar for a couple of turns, but even if you don't have it you can always tutor it, or just cast Infestation and create hordes of zombies (krovikans are better than squees if you have a squee too, and even without squee they come back many times if you have other creatures). Even without Infestation, you can cast a Skullclamp and start clamping Shadows and Squees (yes, with some moxs in play you cast squee and clamp it every turn, drawing 2 cards for 3R, not so bad).
When you start having a quite big graveyard, the decks runs like mad: bazaars become less useful, and you create zombies with infestation (discarding squees and krovikan every turn, and if you are careful krovikans come back EVERY turn), clamp them with double skullclamp, then discarding 2 and paying 2 to draw 4, which means you can spend 2 to draw 2, or spend 2 to create a zombie (since 2 cards can become a zombie).
Some care is important when discarding creatures: shadows go down first (they can back for free, attack, and then are clamped), then you discard ghouls, krovikans, and squee. Note that all returning effects trigger in the upkeep (except krovikan which triggers at every end of turn), but ghoul's one is not triggered, but activated! This means that in your upkeep, even if Ghoul does not have enough creture above it, you can take back squees under it, discard them through bazaar or infestation and then, still in the upkeep, make the Ghoul come back paying B.
After a general overview of the deck, here there are some comments on specific cards:
- Anger. The red splash was made to be able to play squee, which is useful when screwed, but with red anger becomes really good: many creatures have haste already, but no zombie have it. With Anger you can create a Zombies, attack, and then double clamp all of them, making damage AND drawing.
- Library. When the deck starts rolling, it draws like mad, getting hands of 10 cards easily. Library makes the draw engine even wicker.
- Nim Devourer. For those who doesn't know him:
3BB (5), Creature - Zombie 4/1
Nim Devourer gets +1/+0 for each artifact you control.

{B}: Return Nim Devourer from your graveyard to play, then sacrifice a creature. Play this ability only during your upkeep.
With all the artifacts (jewelry and skullclamps) this can become really big. It doesn't have haste (unless you buried Anger too) and it even lack trample, but it's really a big critter (useful to block big guys too, at worst), and come back easily if you sacrifice a new reborn Shadow or a Zombie single-clamped the turn before (in that case you also draw 2). Only one however, since it costs a bit to put it into play, and needs another creature in play too.
- Krovikan Horror. Do not treat it just like another Squee. The ping ability can be very nasty, and it's useful to sacrifice a single-clamped zombie when you don't have two skullclamps yet.
And now some cards that were considered both for main and sideboard, but did not make the cut (still haven't make a side yet, however):
-Plaguebearer
1B (2), Creature - Zombie 1/1

{X}{B}: Destroy target nonblack creature with converted mana cost equal to X.
A way to keep zoo and other similar decks in check the first turns. Too bad it's a bit slow.
- Nezumi Bone-Reader
1B (2), Creature - Rat Shaman 1/1

, Sacrifice a creature: Target player discards a card. Play this ability only any time you could play a sorcery.
Another interesting way to use the ever-coming-back creatures. But there are better ways to use them, skullclamp is much better.
- Grim Lavamancer
A faster way than Krovikan to keep creatures in check, it's also useful to remove some cards and let the Krovikan come back again if you were forced to discard a non-creature on top of the Krovikan
- Firestorm
R (1), Instant
As an additional cost to play Firestorm, discard X cards.
Firestorm deals X damage to each of X target creatures and/or players.
This indeed can do a lot of damage in this deck.
- Abyssal Gatekeeper
1B (2), Creature - Gatekeeper 1/1
When Abyssal Gatekeeper is put into a graveyard from play, each player sacrifices a creature.
Creatures are always good, since they help the other creatures come back when they die. This one's effect is not much for us, but is a lot for the opponent. And it's a good way to take care of colossus too!
- Urborg Justice
BB (2), Instant
Target opponent sacrifices a number of creatures equal to the number of creatures put into your graveyard from play this turn.
Useless at the beginning, becomes a wrath of god when the deck is rolling.
- Delraich
6B (7), Creature - Horror 6/6
Trample
You may sacrifice three black creatures rather than pay Delraich's mana cost.
Three creatures aren't much for this deck, and this guy is big and tramples (and also has a wonderful art!). But it is too much a dead card at the beginning, even if you can discard it, and it counts as a creature to make the others come back.
- Gorilla Shaman
It's a creature. It's a fast drop, and can slow opponents (particularly together with wastelands)
- Crucible of Worlds
With Wastelands and Strip can slow down the oppoenent and even lock him (very good with MoxMonkey), and also let use take back stripped Bazaars. Could also let us play a mono cabal pit
Cabal Pit
Land

: Add

to your mana pool. Cabal Pit deals 1 damage to you.
Threshold -

,

, Sacrifice Cabal Pit: Target creature gets -2/-2 until end of turn. (Play this ability only if seven or more cards are in your graveyard.)
- Cabal Therapy
If we want to control, this is very nice here.
- Duress
A classic, useful before a Therapy. The problem with this and the above is that they tend to diluite the engine, and could after all be not enough to stop oppoenent's nasty plays.
- Contamination
2B (3), Enchantment
If a land is tapped for mana, it produces

instead of its normal type and amount.
At the beginning of your upkeep, sacrifice Contamination unless you sacrifice a creature.
This is REALLY evil! Together with Gorilla Shaman could be really nasty.
- Buried Alive
2B (3), Sorcery
Search your library for up to three creature cards and put them into your graveyard. Then shuffle your library.
The deck runs fine without them, but it's undeniable that a first turn ritual->buried alive would set the game in the right direction.
- Death Spark
R (1), Instant
Death Spark deals 1 damage to target creature or player.
At the beginning of your upkeep, if Death Spark is in your graveyard with a creature card directly above it, you may pay

. If you do, return Death Spark to your hand.
Can be reused multiple times, and it's even a card that comes back (this plus squee is like having two squees). Too bad that the cost of 1 could be not so low as it seems. To make damage, firestorm is usually much better.
- Rack and Ruin
A classic against artifacts
- Mind Slash
1BB (3), Enchantment

, Sacrifice a creature: Target opponent reveals his or her hand. Choose a card from it. That player discards that card. Play this ability only any time you could play a sorcery.
Better than duress! It's a pity it costs a bit too much.
- Myr Servitor
1, Artifact Creature - Myr 1/1
At the beginning of your upkeep, if Myr Servitor is in play, each player returns all cards named Myr Servitor from his or her graveyard to play.
Another recurring creature, but this need other of its kind in play. It's quite slow to start working, and recurring monsters are already enough anyway.
- Genesis Chamber
An interesting option to create a really big army
- Gate to Phyrexia
To destroy an artifact each turn (could also be just a mox for a mana denial plan)
- Chalice of the Void
When we start rolling, we could set ANY value, since we do not cast anything anymore. Chalice for zero can be played with not much trouble, but at 1 he have skullclamp and at 2 the Infestation. We can leave with just one of the two, but it's not good anyway. This however could harm the opponent more than us, and it's a good way toavoid Tormod's Crypts.
- Pyrostatic Pillar
We cast very few spells, this would hurt our opponent a lot.
-Carrion Feeder
B (1), Creature - Zombie 1/1
Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.
-Pithing Needle
Excellent to avoid the Tormod's Crypt problem, and for many other problems,
Can become really big, but skullclamp is a better way to use creatures.
-Plague Spitter
2B (3), Creature - Horror 2/2
At the beginning of your upkeep, Plague Spitter deals 1 damage to each creature and each player.
When Plague Spitter is put into a graveyard from play, Plague Spitter deals 1 damage to each creature and each player.
Interesting card against swarms of creatures, but it kills even ours a bit too much, since if killed it kills our zombies too.
- Grave Pact
1BBB (4), Enchantment
Whenever a creature you control is put into a graveyard from play, each other player sacrifices a creature.
A classic card for a deck like this, but a bit too mana intensitive.
So any suggestion is well appreciated! Nothing beats the satisfaction of playing a funny undeads deck with an avatar representing a lich!
