Boros Guildmage

{1}{R}: Target creature gains haste until end of turn.
{1}{W}: Target creature gains first strike until end of turn.

Eiganjo Uprising

Create X 2/2 white Samurai creature tokens with vigilance. They gain menace and haste until end of turn.
Each opponent creates X minus one 2/2 white Samurai creature tokens with vigilance.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Mountain

Fanatical Firebrand

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}, Sacrifice this creature: It deals 1 damage to any target.

Crackling Emergence

Enchant land you control
Enchanted land is a 3/3 red Spirit creature with haste. It's still a land.
If enchanted land would be destroyed, instead sacrifice this Aura and that land gains indestructible until end of turn.

Devastating Onslaught

Create X tokens that are copies of target artifact or creature you control. Those tokens gain haste until end of turn. Sacrifice them at the beginning of the next end step.

Bogardan Dragonheart

Sacrifice another creature: Until end of turn, this creature becomes a Dragon with base power and toughness 4/4, flying, and haste.

Angelfire Ignition

Put two +1/+1 counters on target creature. It gains vigilance, trample, lifelink, indestructible, and haste until end of turn.
Flashback {2}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Plains

Ash, Party Crasher

Haste
Celebration — Whenever Ash attacks, if two or more nonland permanents entered the battlefield under your control this turn, put a +1/+1 counter on Ash.

Arni Brokenbrow

Haste
Boast — {1}: You may change Arni's base power to 1 plus the greatest power among other creatures you control until end of turn. (Activate only if this creature attacked this turn and only once each turn.)

Crimson Mage

{R}: Target creature you control gains haste until end of turn. (It can attack and {T} this turn.)

Coiling Stalker

Ninjutsu {1}{G} ({1}{G}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, put a +1/+1 counter on target creature you control that doesn't have a +1/+1 counter on it.

Rainbow Dash

Flying, haste
Whenever a creature you control with flying and/or haste attacks, you get 20% cooler. (You start at 0% coolness.)
Sonic Rainboom — {T}: If you're at least 100% cool, add {W}{U}{B}{R}{G}, draw a card, and reset your coolness.

Amonkhet Raceway

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
{T}: Add {C}.
Max speed — {T}: Target creature gains haste until end of turn.

Cerodon Yearling

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Clockwork Percussionist

Haste
When this creature dies, exile the top card of your library. You may play it until the end of your next turn.