Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Fang Skulkin

{2}: Target black creature gains wither until end of turn. (It deals damage to creatures in the form of -1/-1 counters.)

Bonehoard

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards.
Equip {2}

Ward of Bones

Each opponent who controls more creatures than you can't cast creature spells. The same is true for artifacts and enchantments.
Each opponent who controls more lands than you can't play lands.

Island

Kjeldoran Dead

When Kjeldoran Dead enters, sacrifice a creature.
{B}: Regenerate Kjeldoran Dead.

Diabolic Revelation

Search your library for up to X cards, put those cards into your hand, then shuffle.

Death Baron

Skeletons you control and other Zombies you control get +1/+1 and have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)

Flayed Nim

Whenever Flayed Nim deals combat damage to a creature, that creature's controller loses that much life.
{2}{B}: Regenerate Flayed Nim.

Skeletal Scrying

As an additional cost to cast this spell, exile X cards from your graveyard.
You draw X cards and you lose X life.

Augur of Skulls

{1}{B}: Regenerate Augur of Skulls.
Sacrifice Augur of Skulls: Target player discards two cards. Activate only during your upkeep.

Skull Catapult

{1}, {T}, Sacrifice a creature: Skull Catapult deals 2 damage to any target.

Urborg Skeleton

Kicker {3} (You may pay an additional {3} as you cast this spell.)
{B}: Regenerate Urborg Skeleton.
If Urborg Skeleton was kicked, it enters with a +1/+1 counter on it.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Contamination

At the beginning of your upkeep, sacrifice Contamination unless you sacrifice a creature.
If a land is tapped for mana, it produces {B} instead of any other type and amount.

Marrow Bats

Flying
Pay 4 life: Regenerate Marrow Bats.

Drudge Reavers

Flash (You may cast this spell any time you could cast an instant.)
{B}: Regenerate Drudge Reavers.

Champion of Stray Souls

{3}{B}{B}, {T}, Sacrifice X other creatures: Return X target creature cards from your graveyard to the battlefield.
{5}{B}{B}: Put Champion of Stray Souls on top of your library from your graveyard.

Phyrexian Monitor

Carrionette

{2}{B}{B}: Exile Carrionette and target creature unless that creature's controller pays {2}. Activate only if Carrionette is in your graveyard.

Paragon of Open Graves

Other black creatures you control get +1/+1.
{2}{B}, {T}: Another target black creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Shell Skulkin

{3}: Target blue creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Future Sight

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Lake of the Dead

If Lake of the Dead would enter, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Skeletal Wurm

Submerged Boneyard

Submerged Boneyard enters tapped.
{T}: Add {U} or {B}.

Spawning Pool

Spawning Pool enters tapped.
{T}: Add {B}.
{1}{B}: Spawning Pool becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Skeleton Ship

When you control no Islands, sacrifice Skeleton Ship.
{T}: Put a -1/-1 counter on target creature.

Restless Dead

Lim-Dûl's Vault

Look at the top five cards of your library. As many times as you choose, you may pay 1 life, put those cards on the bottom of your library in any order, then look at the top five cards of your library. Then shuffle and put the last cards you looked at this way on top in any order.

Mortus Strider

When Mortus Strider dies, return it to its owner's hand.

Skull of Ramos

{T}: Add {B}.
Sacrifice Skull of Ramos: Add {B}.

Grave Betrayal

Whenever a creature you don't control dies, return it to the battlefield under your control with an additional +1/+1 counter on it at the beginning of the next end step. That creature is a black Zombie in addition to its other colors and types.

Unworthy Dead

Death Wind

Target creature gets -X/-X until end of turn.

Tenacious Dead

When Tenacious Dead dies, you may pay {1}{B}. If you do, return it to the battlefield tapped under its owner's control.

Bottomless Vault

Bottomless Vault enters tapped.
You may choose not to untap Bottomless Vault during your untap step.
At the beginning of your upkeep, if Bottomless Vault is tapped, put a storage counter on it.
{T}, Remove any number of storage counters from Bottomless Vault: Add {B} for each storage counter removed this way.

Manor Skeleton

Artificer's Hex

Enchant Equipment
At the beginning of your upkeep, if enchanted Equipment is attached to a creature, destroy that creature.

Dimir House Guard

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Sacrifice a creature: Regenerate Dimir House Guard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Lim-Dûl's High Guard

First strike
{1}{B}: Regenerate Lim-Dûl's High Guard.

Wall of Bone

Defender (This creature can't attack.)
{B}: Regenerate Wall of Bone. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Skithiryx, the Blight Dragon

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{B}: Skithiryx, the Blight Dragon gains haste until end of turn.
{B}{B}: Regenerate Skithiryx.

Skeletal Vampire

Flying
When Skeletal Vampire enters, create two 1/1 black Bat creature tokens with flying.
{3}{B}{B}, Sacrifice a Bat: Create two 1/1 black Bat creature tokens with flying.
Sacrifice a Bat: Regenerate Skeletal Vampire.

Casting of Bones

Enchant creature
When enchanted creature dies, draw three cards, then discard one of them.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

All Hallow's Eve

Exile All Hallow's Eve with two scream counters on it.
At the beginning of your upkeep, if All Hallow's Eve is exiled with a scream counter on it, remove a scream counter from it. If there are no more scream counters on it, put it into your graveyard and each player returns all creature cards from their graveyard to the battlefield.

Bone to Ash

Counter target creature spell.
Draw a card.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Restless Bones

{3}{B}, {T}: Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)
{1}{B}: Regenerate Restless Bones.

Grave Exchange

Return target creature card from your graveyard to your hand. Target player sacrifices a creature of their choice.

Glistening Oil

Enchant creature
Enchanted creature has infect.
At the beginning of your upkeep, put a -1/-1 counter on enchanted creature.
When Glistening Oil is put into a graveyard from the battlefield, return Glistening Oil to its owner's hand.

Swamp

Chill to the Bone

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Remove Soul

Drake-Skull Cameo

Spine of Ish Sah

When Spine of Ish Sah enters, destroy target permanent.
When Spine of Ish Sah is put into a graveyard from the battlefield, return Spine of Ish Sah to its owner's hand.

Skeletal Changeling

Changeling (This card is every creature type.)
{1}{B}: Regenerate Skeletal Changeling.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Jwar Isle Refuge

Jwar Isle Refuge enters tapped.
When Jwar Isle Refuge enters, you gain 1 life.
{T}: Add {U} or {B}.

Cinderbones

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{1}{B}: Regenerate Cinderbones.

Bone Harvest

Put any number of target creature cards from your graveyard on top of your library.
Draw a card at the beginning of the next turn's upkeep.

Kathari Remnant

Flying
{B}: Regenerate Kathari Remnant.
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Batterskull

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +4/+4 and has vigilance and lifelink.
{3}: Return Batterskull to its owner's hand.
Equip {5}

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Oubliette

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)