Plague Beetle

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Dauthi Horror

Shadow (This creature can block or be blocked by only creatures with shadow.)
This creature can't be blocked by white creatures.

Gonti, Night Minister

Whenever a player casts a spell they don't own, that player creates a Treasure token.
Whenever a creature deals combat damage to one of your opponents, its controller looks at the top card of that opponent's library and exiles it face down. They may play that card for as long as it remains exiled. Mana of any type can be spent to cast a spell this way.

Tormented Soul

This creature can't block and can't be blocked.

Clockwork Droid

You may exert this creature as it attacks. When you do, it can't be blocked this turn and you scry 1. (An exerted creature won't untap during your next untap step. To scry 1, look at the top card of your library. You may put that card on the bottom.)

Squirming Mass

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Rancid Rats

Skulk (This creature can't be blocked by creatures with greater power.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Highborn Ghoul

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Prickly Boggart

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}: This creature gets +1/+1 until end of turn.

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return this card from your graveyard to the battlefield.

Nezumi Cutthroat

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
This creature can't block.

Bog Imp

Flying (This creature can't be blocked except by creatures with flying or reach.)

Vampire Cutthroat

Skulk (This creature can't be blocked by creatures with greater power.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Frightcrawler

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Threshold — As long as seven or more cards are in your graveyard, this creature gets +2/+2 and can't block.

Pale Rider of Trostad

Skulk (This creature can't be blocked by creatures with greater power.)
When this creature enters, discard a card.

Thieving Varmint

Deathtouch, lifelink
{T}, Pay 1 life: Add two mana of any one color. Spend this mana only to cast spells you don't own.

Vampire Bats

Flying (This creature can't be blocked except by creatures with flying or reach.)
{B}: This creature gets +1/+0 until end of turn. Activate no more than twice each turn.

Ebony Charm

Choose one —
• Target opponent loses 1 life and you gain 1 life.
• Exile up to three target cards from a single graveyard.
• Target creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Shadow Alley Denizen

Whenever another black creature you control enters, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Blightbeetle

Protection from green (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything green.)
Creatures your opponents control can't have +1/+1 counters put on them.