Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Wrathful Red Dragon

Flying
Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

Dromad Purebred

Whenever Dromad Purebred is dealt damage, you gain 1 life.

Forerunner of the Empire

When Forerunner of the Empire enters, you may search your library for a Dinosaur card, reveal it, then shuffle and put that card on top.
Whenever a Dinosaur you control enters, you may have Forerunner of the Empire deal 1 damage to each creature.

Cho-Manno, Revolutionary

Prevent all damage that would be dealt to Cho-Manno, Revolutionary.

Hungering Hydra

Hungering Hydra enters with X +1/+1 counters on it.
Hungering Hydra can't be blocked by more than one creature.
Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Overgrown Armasaur

Enrage — Whenever Overgrown Armasaur is dealt damage, create a 1/1 green Saproling creature token.

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Wayta, Trainer Prodigy

Haste
{2}{G}, {T}: Target creature you control fights another target creature. This ability costs {2} less to activate if it targets two creatures you control.
If a creature you control being dealt damage causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Polyraptor

Enrage — Whenever Polyraptor is dealt damage, create a token that's a copy of Polyraptor.

Vrondiss, Rage of Ancients

Enrage — Whenever Vrondiss, Rage of Ancients is dealt damage, you may create a 5/4 red and green Dragon Spirit creature token with "When this creature deals damage, sacrifice it."
Whenever you roll one or more dice, you may have Vrondiss deal 1 damage to itself.

Sprouting Phytohydra

Defender (This creature can't attack.)
Whenever Sprouting Phytohydra is dealt damage, you may create a token that's a copy of Sprouting Phytohydra.

Dawn Elemental

Flying
Prevent all damage that would be dealt to Dawn Elemental.

Fungusaur

Whenever Fungusaur is dealt damage, put a +1/+1 counter on it.

Spidersilk Armor

Creatures you control get +0/+1 and have reach. (They can block creatures with flying.)

Mogg Maniac

Whenever Mogg Maniac is dealt damage, it deals that much damage to target opponent or planeswalker.

Archangel of Strife

Flying
As Archangel of Strife enters, each player chooses war or peace.
Creatures controlled by players who chose war get +3/+0.
Creatures controlled by players who chose peace get +0/+3.

Undergrowth Champion

If damage would be dealt to Undergrowth Champion while it has a +1/+1 counter on it, prevent that damage and remove a +1/+1 counter from Undergrowth Champion.
Landfall — Whenever a land you control enters, put a +1/+1 counter on Undergrowth Champion.

Ravenous Daggertooth

Enrage — Whenever Ravenous Daggertooth is dealt damage, you gain 2 life.

Fiery Confluence

Choose three. You may choose the same mode more than once.
• Fiery Confluence deals 1 damage to each creature.
• Fiery Confluence deals 2 damage to each opponent.
• Destroy target artifact.

Sun-Crowned Hunters

Enrage — Whenever Sun-Crowned Hunters is dealt damage, it deals 3 damage to target opponent or planeswalker.

Subterranean Spirit

Protection from red
{T}: Subterranean Spirit deals 1 damage to each creature without flying.

Cinderclasm

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Cinderclasm deals 1 damage to each creature. If it was kicked, it deals 2 damage to each creature instead.

Hornet Nest

Defender (This creature can't attack.)
Whenever Hornet Nest is dealt damage, create that many 1/1 green Insect creature tokens with flying and deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

Ripjaw Raptor

Enrage — Whenever Ripjaw Raptor is dealt damage, draw a card.

Urban Daggertooth

Vigilance
Enrage — Whenever Urban Daggertooth is dealt damage, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Imperial Ceratops

Enrage — Whenever Imperial Ceratops is dealt damage, you gain 2 life.

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

Flumph

Defender, flying
Whenever Flumph is dealt damage, you and target opponent each draw a card.

Wrathful Raptors

Trample
Whenever a Dinosaur you control is dealt damage, it deals that much damage to any target that isn't a Dinosaur.

Silverclad Ferocidons

Enrage — Whenever Silverclad Ferocidons is dealt damage, each opponent sacrifices a permanent of their choice.

Siegehorn Ceratops

Enrage — Whenever Siegehorn Ceratops is dealt damage, put two +1/+1 counters on it. (It must survive the damage to get the counters.)

Frilled Deathspitter

Enrage — Whenever Frilled Deathspitter is dealt damage, it deals 2 damage to target opponent or planeswalker.

Kami of the Honored Dead

Flying
Whenever Kami of the Honored Dead is dealt damage, you gain that much life.
Soulshift 6 (When this creature dies, you may return target Spirit card with mana value 6 or less from your graveyard to your hand.)

Oathsworn Giant

Vigilance
Other creatures you control get +0/+2 and have vigilance.

Apex Altisaur

When Apex Altisaur enters, it fights up to one target creature you don't control.
Enrage — Whenever Apex Altisaur is dealt damage, it fights up to one target creature you don't control.

Raptor Hatchling

Enrage — Whenever Raptor Hatchling is dealt damage, create a 3/3 green Dinosaur creature token with trample.

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Spitemare

Whenever Spitemare is dealt damage, it deals that much damage to any target.

Deep-Slumber Titan

Deep-Slumber Titan enters tapped.
Deep-Slumber Titan doesn't untap during your untap step.
Whenever Deep-Slumber Titan is dealt damage, untap it.

Wall of Essence

Defender (This creature can't attack.)
Whenever Wall of Essence is dealt combat damage, you gain that much life.

Truefire Captain

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Truefire Captain is dealt damage, it deals that much damage to target player.

Builder's Blessing

Untapped creatures you control get +0/+2.

Feldon, Ronom Excavator

Haste
Feldon, Ronom Excavator can't block.
Whenever Feldon is dealt damage, exile that many cards from the top of your library. Choose one of them. Until the end of your next turn, you may play that card.

Saber Ants

Whenever Saber Ants is dealt damage, you may create that many 1/1 green Insect creature tokens.

Trapjaw Tyrant

Enrage — Whenever Trapjaw Tyrant is dealt damage, exile target creature an opponent controls until Trapjaw Tyrant leaves the battlefield.

Harbinger of the Hunt

Flying
{2}{R}: Harbinger of the Hunt deals 1 damage to each creature without flying.
{2}{G}: Harbinger of the Hunt deals 1 damage to each other creature with flying.

Needletooth Raptor

Enrage — Whenever Needletooth Raptor is dealt damage, it deals 5 damage to target creature an opponent controls.

Ashen Firebeast

{1}{R}: Ashen Firebeast deals 1 damage to each creature without flying.

Metropolis Reformer

Flying, vigilance
You have hexproof.
Whenever Metropolis Reformer is dealt damage, you gain that much life.

Wall of Hope

Defender (This creature can't attack.)
Whenever Wall of Hope is dealt damage, you gain that much life.

Tremor

Tremor deals 1 damage to each creature without flying.

Snapping Sailback

Flash
Enrage — Whenever Snapping Sailback is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Castle

Volcanic Spray

Volcanic Spray deals 1 damage to each creature without flying and each player.
Flashback {1}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Bellowing Aegisaur

Enrage — Whenever Bellowing Aegisaur is dealt damage, put a +1/+1 counter on each other creature you control.

Banishing Coils

Exile target artifact or enchantment. (Then exile this card. You may cast the creature later from exile.)

Guardian Naga

Vigilance
During your turn, prevent all damage that would be dealt to Guardian Naga.