Grendel, Spawn of Knull

Flying (This creature can't be blocked except by creatures with flying or reach.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Venom, Deadly Devourer

Vigilance, menace
{3}: Exile target creature card from a graveyard. When you do, put X +1/+1 counters on target Symbiote, where X is the exiled card's toughness.

Common Crook

When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Tombstone, Career Criminal

When Tombstone enters, return target Villain card from your graveyard to your hand.
Villain spells you cast cost {1} less to cast.

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Agent Venom

Flash
Menace
Whenever another nontoken creature you control dies, you draw a card and lose 1 life.

Swamp

Venom, Evil Unleashed

Deathtouch
{2}{B}, Exile this card from your graveyard: Put two +1/+1 counters on target creature. It gains deathtouch until end of turn. Activate only as a sorcery.

Symbiote Spawn

When this creature dies, each opponent loses 2 life and you gain 2 life.

The Spot's Portal

Put target creature on the bottom of its owner's library. You lose 2 life unless you control a Villain.

Thriving Moor

This land enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Hot Dog Cart

When this artifact enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{T}: Add one mana of any color.

Prison Break

Return target creature card from your graveyard to the battlefield with an additional +1/+1 counter on it.
Mayhem {3}{B} (You may cast this card from your graveyard for {3}{B} if you discarded it this turn. Timing rules still apply.)

Venomized Cat

Deathtouch
When this creature enters, mill two cards. (Put the top two cards of your library into your graveyard.)

Venom's Hunger

This spell costs {2} less to cast if you control a Villain.
Destroy target creature. You gain 2 life.