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.

Valor in Akros

Whenever a creature you control enters, creatures you control get +1/+1 until end of turn.

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)

Fiendlash

Equipped creature gets +2/+0 and has reach.
Whenever equipped creature is dealt damage, it deals damage equal to its power to target player or planeswalker.
Equip {2}{R}

Growing Ranks

At the beginning of your upkeep, populate. (Create a token that's a copy of a creature token you control.)

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Good-Fortune Unicorn

Whenever another creature you control enters, put a +1/+1 counter on that creature.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Druid's Deliverance

Prevent all combat damage that would be dealt to you this turn. Populate. (Create a token that's a copy of a creature token you control.)

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Season of Growth

Whenever a creature you control enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Whenever you cast a spell that targets a creature you control, draw a card.

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on Champion of Lambholt.

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Song of Freyalise

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Until your next turn, creatures you control gain "{T}: Add one mana of any color."
III — Put a +1/+1 counter on each creature you control. Those creatures gain vigilance, trample, and indestructible until end of turn.

Marath, Will of the Wild

Marath, Will of the Wild enters with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.
{X}, Remove X +1/+1 counters from Marath: Choose one —
• Put X +1/+1 counters on target creature. X can't be 0.
• Marath deals X damage to any target. X can't be 0.
• Create an X/X green Elemental creature token. X can't be 0.

Ripjaw Raptor

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

Raptor Hatchling

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

Rite of Passage

Whenever a creature you control is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Trapjaw Tyrant

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

Anointed Procession

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.

Invigorating Surge

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on that creature.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Song of the Worldsoul

Whenever you cast a spell, populate. (Create a token that's a copy of a creature token you control.)

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Frilled Deathspitter

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

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.

Sundering Growth

Destroy target artifact or enchantment, then populate. (Create a token that's a copy of a creature token you control.)