Ukud Cobra

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Triskaidekaphobia

At the beginning of your upkeep, choose one —
• Each player with exactly 13 life loses the game, then each player gains 1 life.
• Each player with exactly 13 life loses the game, then each player loses 1 life.

Sengir Connoisseur

Flying
Whenever one or more other creatures die, put a +1/+1 counter on Sengir Connoisseur. This ability triggers only once each turn.

Swamp

Claim of Erebos

Enchant creature
Enchanted creature has "{1}{B}, {T}: Target player loses 2 life."

Child of Night

Knight of Dusk's Shadow

Menace (This creature can't be blocked except by two or more creatures.)
Your opponents can't gain life.
{1}{B}: Knight of Dusk's Shadow gets +1/+1 until end of turn.

Typhoid Rats

Deep-Cavern Bat

Flying, lifelink
When Deep-Cavern Bat enters, look at target opponent's hand. You may exile a nonland card from it until Deep-Cavern Bat leaves the battlefield.

Hired Poisoner

Tyrannical Pitlord

Flying, trample
As Tyrannical Pitlord enters, choose another creature you control.
The chosen creature gets +3/+3 and has flying.
When Tyrannical Pitlord leaves the battlefield, sacrifice the chosen creature.

Ghastly Gloomhunter

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
Flying, lifelink
If Ghastly Gloomhunter was kicked, it enters with two +1/+1 counters on it.

Hierophant's Chalice

When Hierophant's Chalice enters, target opponent loses 1 life and you gain 1 life.
{T}: Add {C}.

Battlefly Swarm

Flying
{B}: Battlefly Swarm gains deathtouch until end of turn.

Epicure of Blood

Whenever you gain life, each opponent loses 1 life.

Bloodhunter Bat

Flying
When Bloodhunter Bat enters, target player loses 2 life and you gain 2 life.

Profane Memento

Whenever a creature card is put into an opponent's graveyard from anywhere, you gain 1 life.

Blood Burglar

During your turn, Blood Burglar has lifelink.(Damage dealt by this creature also causes you to gain that much life.)

Queen's Agent

Lifelink
When Queen's Agent enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)