Rakdos Trumpeter

Menace (This creature can't be blocked except by two or more creatures.)
{3}{R}: Rakdos Trumpeter gets +2/+0 until end of turn.

Moonrise Intruder

Menace (This creature can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Moonrise Intruder.

Village Messenger

Haste
At the beginning of each upkeep, if no spells were cast last turn, transform Village Messenger.

Village Messenger // Moonrise Intruder

Deputized Protester

Menace (This creature can't be blocked except by two or more creatures.)
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

Trynn, Champion of Freedom

Partner with Silvar, Devourer of the Free (When this creature enters, target player may put Silvar into their hand from their library, then shuffle.)
At the beginning of your end step, if you attacked this turn, create a 1/1 white Human Soldier creature token.

Frillscare Mentor

When Frillscare Mentor enters, put a menace counter on target non-Human creature you control. (It can't be blocked except by two or more creatures.)
{2}{R}, {T}: Put a +1/+1 counter on each creature you control with menace.

Piper of the Swarm

Rats you control have menace.
{1}{B}, {T}: Create a 1/1 black Rat creature token.
{2}{B}{B}, {T}, Sacrifice three Rats: Gain control of target creature.

Nimana Skitter-Sneak

As long as an opponent has eight or more cards in their graveyard, Nimana Skitter-Sneak gets +1/+0 and has menace. (It can't be blocked except by two or more creatures.)

Frontier Warmonger

Whenever one or more creatures attack one of your opponents or a planeswalker they control, those creatures gain menace until end of turn.

Moodmark Painter

Undergrowth — When Moodmark Painter enters, target creature gains menace and gets +X/+0 until end of turn, where X is the number of creature cards in your graveyard. (It can't be blocked except by two or more creatures.)

Firemantle Mage

Rally — Whenever Firemantle Mage or another Ally you control enters, creatures you control gain menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

Belle of the Brawl

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Belle of the Brawl attacks, other Knights you control get +1/+0 until end of turn.

Blood-Chin Rager

Whenever Blood-Chin Rager attacks, Warrior creatures you control gain menace until end of turn. (They can't be blocked except by two or more creatures.)

Dire Fleet Interloper

Menace
When Dire Fleet Interloper 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.)

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

Silvar, Devourer of the Free

Partner with Trynn, Champion of Freedom (When this creature enters, target player may put Trynn into their hand from their library, then shuffle.)
Menace
Sacrifice a Human: Put a +1/+1 counter on Silvar, Devourer of the Free. It gains indestructible until end of turn.

Sonorous Howlbonder

Menace
Each creature you control with menace can't be blocked except by three or more creatures.

Ghor-Clan Wrecker

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Menace (This creature can't be blocked except by two or more creatures.)

Goblin War Drums

Creatures you control have menace. (They can't be blocked except by two or more creatures.)

Blackbloom Bog

Blackbloom Bog enters tapped.
{T}: Add {B}.

Blackbloom Rogue

Menace (This creature can't be blocked except by two or more creatures.)
Blackbloom Rogue gets +3/+0 as long as an opponent has eight or more cards in their graveyard.

Blackbloom Rogue // Blackbloom Bog

Tomb Robber

Menace
{1}, Discard a card: Tomb Robber 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.)

Fathom Fleet Captain

Menace
Whenever Fathom Fleet Captain attacks, if you control another nontoken Pirate, you may pay {2}. If you do, create a 2/2 black Pirate creature token with menace.

Nikara, Lair Scavenger

Partner with Yannik, Scavenging Sentinel (When this creature enters, target player may put Yannik into their hand from their library, then shuffle.)
Menace
Whenever another creature you control leaves the battlefield, if it had one or more counters on it, you draw a card and you lose 1 life.

Stormblood Berserker

Bloodthirst 2 (If an opponent was dealt damage this turn, this creature enters with two +1/+1 counters on it.)
Menace (This creature can't be blocked except by two or more creatures.)

Gatstaf Ravagers

Menace (This creature can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Gatstaf Ravagers.

Gatstaf Arsonists

At the beginning of each upkeep, if no spells were cast last turn, transform Gatstaf Arsonists.

Gatstaf Arsonists // Gatstaf Ravagers

Kari Zev, Skyship Raider

First strike, menace
Whenever Kari Zev, Skyship Raider attacks, create Ragavan, a legendary 2/1 red Monkey creature token. Ragavan enters tapped and attacking. Exile that token at end of combat.

Elite Headhunter

Menace (This creature can't be blocked except by two or more creatures.)
{B/R}{B/R}{B/R}, Sacrifice another creature or an artifact: Elite Headhunter deals 2 damage to target creature or planeswalker.

Greven, Predator Captain

Menace
Greven, Predator Captain gets +X/+0, where X is the amount of life you've lost this turn.
Whenever Greven attacks, you may sacrifice another creature. If you do, you draw cards equal to that creature's power and you lose life equal to that creature's toughness.

Sweatworks Brawler

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Menace

Glint-Sleeve Siphoner

Menace
Whenever Glint-Sleeve Siphoner enters or attacks, you get {E} (an energy counter).
At the beginning of your upkeep, you may pay {E}{E}. If you do, you draw a card and you lose 1 life.

Maulfist Squad

Menace
Fabricate 1 (When this creature enters, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)

Sanctuary Lockdown

Humans you control get +1/+1.
{2}, Tap two untapped Humans you control: Tap target creature an opponent controls.

Stronghold Confessor

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Menace (This creature can't be blocked except by two or more creatures.)
If Stronghold Confessor was kicked, it enters with two +1/+1 counters on it.

Embraal Bruiser

Embraal Bruiser enters tapped.
Embraal Bruiser has menace as long as you control an artifact.

Terror of Kruin Pass

Double strike
Werewolves you control have menace. (They can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Terror of Kruin Pass.

Kruin Outlaw

First strike
At the beginning of each upkeep, if no spells were cast last turn, transform Kruin Outlaw.

Kruin Outlaw // Terror of Kruin Pass

Dreamstealer

Menace
Whenever Dreamstealer deals combat damage to a player, that player discards that many cards.
Eternalize {4}{B}{B} ({4}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Human Wizard with no mana cost. Eternalize only as a sorcery.)

Locthwain Paladin

Menace (This creature can't be blocked except by two or more creatures.)
Adamant — If at least three black mana was spent to cast this spell, Locthwain Paladin enters with a +1/+1 counter on it.