Fang of the Pack

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
At the beginning of combat on your turn, another target creature you control gains melee until end of turn. (If a creature has multiple instances of melee, each triggers separately.)

Aggressive Mammoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other creatures you control have trample.

Urabrask the Hidden

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

Resilient Khenra

When Resilient Khenra enters, you may have target creature get +X/+X until end of turn, where X is Resilient Khenra's power.
Eternalize {4}{G}{G} ({4}{G}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Jackal Wizard with no mana cost. Eternalize only as a sorcery.)

Rampaging Brontodon

Trample
Whenever Rampaging Brontodon attacks, it gets +1/+1 until end of turn for each land you control.

Terra Ravager

Whenever Terra Ravager attacks, it gets +X/+0 until end of turn, where X is the number of lands defending player controls.

Khenra Charioteer

Trample
Other creatures you control have trample.

Wild Beastmaster

Whenever Wild Beastmaster attacks, each other creature you control gets +X/+X until end of turn, where X is Wild Beastmaster's power.

Coastline Marauders

Trample
Whenever Coastline Marauders attacks, it gets +1/+0 until end of turn for each land defending player controls.
Encore {4}{R}{R} ({4}{R}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Syr Faren, the Hengehammer

Whenever Syr Faren, the Hengehammer attacks, another target attacking creature gets +X/+X until end of turn, where X is Syr Faren's power.

Fires of Yavimaya

Creatures you control have haste.
Sacrifice Fires of Yavimaya: Target creature gets +2/+2 until end of turn.

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Arlinn, Embraced by the Moon

+1: Creatures you control get +1/+1 and gain trample until end of turn.
−1: Arlinn, Embraced by the Moon deals 3 damage to any target. Transform Arlinn, Embraced by the Moon.
−6: You get an emblem with "Creatures you control have haste and '{T}: This creature deals damage equal to its power to any target.'"

Arlinn Kord

+1: Until end of turn, up to one target creature gets +2/+2 and gains vigilance and haste.
0: Create a 2/2 green Wolf creature token. Transform Arlinn Kord.

Arlinn Kord // Arlinn, Embraced by the Moon

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Rubblebelt Rioters

Haste
Whenever Rubblebelt Rioters attacks, it gets +X/+0 until end of turn, where X is the greatest power among creatures you control.

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.)

Pathbreaker Ibex

Whenever Pathbreaker Ibex attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Nylea's Forerunner

Rubblebelt Raiders

Whenever Rubblebelt Raiders attacks, put a +1/+1 counter on it for each attacking creature you control.

Tuya Bearclaw

Whenever Tuya Bearclaw attacks, it gets +X/+X until end of turn, where X is the greatest power among other creatures you control.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Cultivator of Blades

Fabricate 2 (When this creature enters, put two +1/+1 counters on it or create two 1/1 colorless Servo artifact creature tokens.)
Whenever Cultivator of Blades attacks, you may have other attacking creatures get +X/+X until end of turn, where X is Cultivator of Blades's power.

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Gruul Beastmaster

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever Gruul Beastmaster attacks, another target creature you control gets +X/+0 until end of turn, where X is Gruul Beastmaster's power.