Endless One

Endless One enters with X +1/+1 counters on it.

Arachnoform

Enchant creature
Enchanted creature gets +2/+2, has reach, and is every creature type.

Sparkspitter

{R}, {T}, Discard a card: Create a 3/1 red Elemental creature token named Spark Elemental. It has trample, haste, and "At the beginning of the end step, sacrifice Spark Elemental."

Rebellion of the Flamekin

Whenever you clash, you may pay {1}. If you do, create a 3/1 red Elemental Shaman creature token. If you won, that token gains haste until end of turn. (This ability triggers after the clash ends.)

Fiery Emancipation

If a source you control would deal damage to a permanent or player, it deals triple that damage to that permanent or player instead.

Aether Web

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1, has reach, and can block creatures with shadow as though they didn't have shadow. (Creatures with reach can block creatures with flying.)

Arboretum Elemental

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Glorious Sunrise

At the beginning of combat on your turn, choose one —
• Creatures you control get +1/+1 and gain trample until end of turn.
• Target land gains "{T}: Add {G}{G}{G}" until end of turn.
• Draw a card if you control a creature with power 3 or greater.
• You gain 3 life.

Primal Command

Choose two —
• Target player gains 7 life.
• Put target noncreature permanent on top of its owner's library.
• Target player shuffles their graveyard into their library.
• Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on it.

Forest

Mountain

Conifer Strider

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Scorch Spitter

Whenever Scorch Spitter attacks, it deals 1 damage to the player or planeswalker it's attacking.

Chandra's Pyreling

Whenever a source you control deals noncombat damage to an opponent, Chandra's Pyreling gets +1/+0 and gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Vine Mare

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Vine Mare can't be blocked by black creatures.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Scampering Scorcher

When Scampering Scorcher enters, create two 1/1 red Elemental creature tokens. Elementals you control gain haste until end of turn. (They can attack and {T} this turn.)

Nova Chaser

Trample
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Living Hive

Trample
Whenever Living Hive deals combat damage to a player, create that many 1/1 green Insect creature tokens.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.