Keeper of Secrets

First strike, haste
Symphony of Pain — Whenever you cast a spell from anywhere other than your hand, this creature deals damage equal to that spell's mana value to target opponent.

Purphoros, Bronze-Blooded

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Other creatures you control have haste.
{2}{R}: You may put a red creature card or an artifact creature card from your hand onto the battlefield. Sacrifice it at the beginning of the next end step.

Craterhoof Behemoth

Haste
When this creature enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Concordant Crossroads

Klauth, Unrivaled Ancient

Flying, haste
Whenever Klauth attacks, add X mana in any combination of colors, where X is the total power of attacking creatures. Spend this mana only to cast spells. Until end of turn, you don't lose this mana as steps and phases end.

Samut, the Tested

+1: Up to one target creature gains double strike until end of turn.
−2: Samut deals 2 damage divided as you choose among one or two targets.
−7: Search your library for up to two creature and/or planeswalker cards, put them onto the battlefield, then shuffle.

Questing Beast

Vigilance, deathtouch, haste
Questing Beast can't be blocked by creatures with power 2 or less.
Combat damage that would be dealt by creatures you control can't be prevented.
Whenever Questing Beast deals combat damage to an opponent, it deals that much damage to target planeswalker that player controls.

Samut, Voice of Dissent

Flash
Double strike, vigilance, haste
Other creatures you control have haste.
{W}, {T}: Untap another target creature.

Hellkite Courser

Flying
When this creature enters, you may put a commander you own from the command zone onto the battlefield. It gains haste. Return it to the command zone at the beginning of the next end step.

Slicer, High-Speed Antagonist

Living metal (During your turn, this Vehicle is also a creature.)
First strike, haste
Whenever Slicer deals combat damage to a player, convert it at end of combat.

Slicer, Hired Muscle

More Than Meets the Eye {2}{R} (You may cast this card converted for {2}{R}.)
Double strike, haste
At the beginning of each opponent's upkeep, you may have that player gain control of Slicer until end of turn. If you do, untap Slicer, goad it, and it can't be sacrificed this turn. If you don't, convert it.

Slicer, Hired Muscle // Slicer, High-Speed Antagonist

Flamerush Rider

Whenever this creature attacks, create a token that's a copy of another target attacking creature and that's tapped and attacking. Exile the token at end of combat.
Dash {2}{R}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Death-Greeter's Champion

Dash {3}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Double strike

Ragavan, Nimble Pilferer

Whenever Ragavan deals combat damage to a player, create a Treasure token and exile the top card of that player's library. Until end of turn, you may cast that card.
Dash {1}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Xenagos, God of Revels

Indestructible
As long as your devotion to red and green is less than seven, Xenagos isn't a creature.
At the beginning of combat on your turn, another target creature you control gains haste and gets +X/+X until end of turn, where X is that creature's power.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Tyrranax Rex

This spell can't be countered.
Trample, ward {4}, haste
Toxic 4 (Players dealt combat damage by this creature also get four poison counters.)

Rabbit Battery

Haste
Equipped creature gets +1/+1 and has haste.
Reconfigure {R} ({R}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Samut, Tyrant Smasher

Creatures you control have haste.
−1: Target creature gets +2/+1 and gains haste until end of turn. Scry 1.

Command Tower

Deathleaper, Terror Weapon

Flash
Haste
Flesh Hooks — Creatures you control that entered this turn have double strike.

Sol Ring

Atalan Jackal

Trample, haste
Skilled Outrider — Whenever this creature deals combat damage to a player, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Samut's Sprint

Target creature gets +2/+1 and gains haste until end of turn. Scry 1.

Urabrask the Hidden

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

Goldspan Dragon

Flying, haste
Whenever this creature attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Taiga

End-Raze Forerunners

Vigilance, trample, haste
When this creature enters, other creatures you control get +2/+2 and gain vigilance and trample until end of turn.

Laelia, the Blade Reforged

Haste
Whenever Laelia attacks, exile the top card of your library. You may play that card this turn.
Whenever one or more cards are put into exile from your library and/or your graveyard, put a +1/+1 counter on Laelia.

Ardoz, Cobbler of War

Haste
Whenever Ardoz 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.