Dogpile

Dogpile deals damage to any target equal to the number of attacking creatures you control.

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Underworld Rage-Hound

Underworld Rage-Hound attacks each combat if able.
Escape—{3}{R}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Underworld Rage-Hound escapes with a +1/+1 counter on it.

Dragon Mantle

Enchant creature
When Dragon Mantle enters, draw a card.
Enchanted creature has "{R}: This creature gets +1/+0 until end of turn."

Dragonrage

Add {R} for each attacking creature you control. Until end of turn, attacking creatures you control gain "{R}: This creature gets +1/+0 until end of turn."

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Ghitu War Cry

{R}: Target creature gets +1/+0 until end of turn.

Lunar Frenzy

Target creature you control gets +X/+0 and gains first strike and trample until end of turn.

Ambitious Assault

Creatures you control get +2/+0 until end of turn. If you control a modified creature, draw a card. (Equipment, Auras you control, and counters are modifications.)

Akki Battle Squad

Whenever one or more modified creatures you control attack, untap all modified creatures you control. After this phase, there is an additional combat phase. This ability triggers only once each turn. (Equipment, Auras you control, and counters are modifications.)

Captive Flame

Volcanic Geyser

Volcanic Geyser deals X damage to any target.

Volt Charge

Volt Charge deals 3 damage to any target. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Lightning Hounds

Hound of Griselbrand

Double strike
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Thundering Raiju

Haste
Whenever Thundering Raiju attacks, put a +1/+1 counter on target creature you control. Then Thundering Raiju deals X damage to each opponent, where X is the number of modified creatures you control other than Thundering Raiju. (Equipment, Auras you control, and counters are modifications.)

War Cadence

{X}{R}: This turn, creatures can't block unless their controller pays {X} for each blocking creature they control.

Two-Headed Cerberus

Double strike (This creature deals both first-strike and regular combat damage.)

Mirror-Style Master

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.)
Whenever this creature attacks, for each attacking modified creature you control, create a tapped and attacking token that's a copy of that creature. Exile those tokens at end of combat. (Equipment, Auras you control, and counters are modifications.)

Progenitor's Icon

As Progenitor's Icon enters, choose a creature type.
{T}: Add one mana of any color.
{T}: The next spell of the chosen type you cast this turn can be cast as though it had flash.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Ashmouth Hound

Whenever Ashmouth Hound blocks or becomes blocked by a creature, Ashmouth Hound deals 1 damage to that creature.

Goldhound

First strike
Menace (This creature can't be blocked except by two or more creatures.)
{T}, Sacrifice Goldhound: Add one mana of any color.

Chandra's Magmutt

{T}: Chandra's Magmutt deals 1 damage to target player or planeswalker.

Bolt Hound

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever Bolt Hound attacks, other creatures you control get +1/+0 until end of turn.

Rage Forger

When Rage Forger enters, put a +1/+1 counter on each other Shaman creature you control.
Whenever a creature you control with a +1/+1 counter on it attacks, you may have that creature deal 1 damage to target player or planeswalker.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Scrapwork Mutt

When Scrapwork Mutt enters, you may discard a card. If you do, draw a card.
Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Immolating Souleater

{R/P}: Immolating Souleater gets +1/+0 until end of turn. ({R/P} can be paid with either {R} or 2 life.)

Igneous Cur

{1}{R}: Igneous Cur gets +2/+0 until end of turn.

Soul's Fire

Target creature you control deals damage equal to its power to any target.

Arcbound Tracker

Menace
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Whenever you cast a spell other than your first spell each turn, put a +1/+1 counter on Arcbound Tracker.

Fiery Hellhound

{R}: Fiery Hellhound gets +1/+0 until end of turn.

Falter

Creatures without flying can't block this turn.

Hellfire Mongrel

At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Hellfire Mongrel deals 2 damage to that player.

Castle Embereth

Castle Embereth enters tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.

Balduvian Rage

Target attacking creature gets +X/+0 until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.