Insufferable Balladeer

Vicious Mockery — When Insufferable Balladeer enters, target creature an opponent controls can't block this turn. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Uncivil Unrest

Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)
If a creature you control with a +1/+1 counter on it would deal damage to a permanent or player, it deals double that damage instead.

Ardoz, Cobbler of War

Haste
Whenever Ardoz, Cobbler of War or another creature you control enters, that creature gets +2/+0 until end of turn.
{3}{R}: Create a 1/1 red Goblin creature token with haste. Activate only as a sorcery.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Alena, Kessig Trapper

First strike
{T}: Add an amount of {R} equal to the greatest power among creatures you control that entered this turn.
Partner (You can have two commanders if both have partner.)

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

Coal Stoker

When Coal Stoker enters, if you cast it from your hand, add {R}{R}{R}.

Daybreak Combatants

Haste (This creature can attack and {T} as soon as it comes under your control.)
When Daybreak Combatants enters, target creature gets +2/+0 until end of turn.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Goblin War Drums

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

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Devilish Valet

Trample, haste
Alliance — Whenever another creature you control enters, double Devilish Valet's power until end of turn.

Tempered in Solitude

Whenever a creature you control attacks alone, exile the top card of your library. You may play that card this turn.

Unstoppable Ogre

When Unstoppable Ogre enters, target creature can't block this turn.

Kruin Striker

Whenever another creature you control enters, Kruin Striker gets +1/+0 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Gimli's Reckless Might

Creatures you control have haste.
Formidable — Whenever you attack, if creatures you control have total power 8 or greater, target attacking creature you control fights up to one target creature you don't control.

Gimli of the Glittering Caves

Double strike
Whenever another legendary creature you control enters, put a +1/+1 counter on Gimli of the Glittering Caves.
Whenever Gimli deals combat damage to a player, create a Treasure token.

Hamletback Goliath

Whenever another creature enters, you may put X +1/+1 counters on Hamletback Goliath, where X is that creature's power.

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Goddric, Cloaked Reveler

Haste
Celebration — As long as two or more nonland permanents entered the battlefield under your control this turn, Goddric, Cloaked Reveler is a Dragon with base power and toughness 4/4, flying, and "{R}: Dragons you control get +1/+0 until end of turn." (It loses all other creature types.)

Arni Metalbrow

Whenever a creature you control attacks or a creature you control enters attacking, you may pay {1}{R}. If you do, you may put a creature card with mana value less than that creature's mana value from your hand onto the battlefield tapped and attacking.