Beetle, Legacy Criminal

Flying
{1}{U}, Exile this card from your graveyard: Put a +1/+1 counter on target creature. It gains flying until end of turn. Activate only as a sorcery.

Stegron the Dinosaur Man

Menace (This creature can't be blocked except by two or more creatures.)
Dinosaur Formula — {1}{R}, Discard this card: Until end of turn, target creature you control gets +3/+1 and becomes a Dinosaur in addition to its other types.

Electro's Bolt

Electro's Bolt deals 4 damage to target creature.
Mayhem {1}{R} (You may cast this card from your graveyard for {1}{R} 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.)

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.)

Scorpion, Seething Striker

Deathtouch
At the beginning of your end step, if a creature died this turn, target creature you control connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Black Cat, Cunning Thief

When Black Cat enters, look at the top nine cards of target opponent's library, exile two of them face down, then put the rest on the bottom of their library in a random order. You may play the exiled cards for as long as they remain exiled. Mana of any type can be spent to cast spells this way.

Mob Lookout

When this creature enters, target creature you control connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Spider-Islanders

Mayhem {1}{R} (You may cast this card from your graveyard for {1}{R} if you discarded it this turn. Timing rules still apply.)

Green Goblin

Flying, menace
Spells you cast from your graveyard cost {2} less to cast.
Goblin Formula — Each nonland card in your graveyard has mayhem. The mayhem cost is equal to its mana cost. (You may cast a card from your graveyard for its mayhem cost if you discarded it this turn. Timing rules still apply.)

Norman Osborn

Norman Osborn can't be blocked.
Whenever Norman Osborn deals combat damage to a player, he connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)
{1}{U}{B}{R}: Transform Norman Osborn. Activate only as a sorcery.

Norman Osborn // Green Goblin

Prowler, Clawed Thief

Menace (This creature can't be blocked except by two or more creatures.)
Whenever another Villain you control enters, Prowler connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

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.

Doc Ock's Henchmen

Flash
Whenever this creature attacks, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

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.")

Scarlet Spider, Kaine

Menace (This creature can't be blocked except by two or more creatures.)
When Scarlet Spider enters, you may discard a card. If you do, put a +1/+1 counter on him.
Mayhem {B/R} (You may cast this card from your graveyard for {B/R} if you discarded it this turn. Timing rules still apply.)

Vulture, Scheming Scavenger

Flying
Whenever Vulture attacks, other Villains you control gain flying until end of turn.

Molten Man, Inferno Incarnate

When Molten Man enters, search your library for a basic Mountain card, put it onto the battlefield tapped, then shuffle.
Molten Man gets +1/+1 for each Mountain you control.
When Molten Man leaves the battlefield, sacrifice a land.

Morbius the Living Vampire

Flying, vigilance, lifelink
{U}{B}, Exile this card from your graveyard: Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Shriek, Treblemaker

At the beginning of your first main phase, you may discard a card. When you do, target creature can't block this turn.
Sonic Blast — Whenever a creature an opponent controls dies, Shriek deals 1 damage to that player.

Mechanical Mobster

When this creature enters, exile up to one target card from a graveyard. Target creature you control connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Chameleon, Master of Disguise

You may have Chameleon enter as a copy of a creature you control, except his name is Chameleon, Master of Disguise.
Mayhem {2}{U} (You may cast this card from your graveyard for {2}{U} if you discarded it this turn. Timing rules still apply.)

Unstable Experiment

Target player draws a card, then up to one target creature you control connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Swarm, Being of Bees

Flash
Flying
Mayhem {B} (You may cast this card from your graveyard for {B} if you discarded it this turn. Timing rules still apply.)

Spider-Slayer, Hatred Honed

Whenever Spider-Slayer deals damage to a Spider, destroy that creature.
{6}, Exile this card from your graveyard: Create two tapped 1/1 colorless Robot artifact creature tokens with flying.

Doc Ock, Sinister Scientist

As long as there are eight or more cards in your graveyard, Doc Ock has base power and toughness 8/8.
As long as you control another Villain, Doc Ock has hexproof. (He can't be the target of spells or abilities your opponents control.)

Inner Demons Gangsters

Discard a card: This creature gets +1/+0 and gains menace until end of turn. Activate only as a sorcery. (It can't be blocked except by two or more creatures.)