Creeping Trailblazer

Other Elementals you control get +1/+0.
{2}{R}{G}: Creeping Trailblazer gets +1/+1 until end of turn for each Elemental you control.

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters, you may return target creature card from your graveyard to your hand.

Brighthearth Banneret

Elemental spells and Warrior spells you cast cost {1} less to cast.
Reinforce 1—{1}{R} ({1}{R}, Discard this card: Put a +1/+1 counter on target creature.)

Incandescent Soulstoke

Other Elemental creatures you control get +1/+1.
{1}{R}, {T}: You may put an Elemental creature card from your hand onto the battlefield. That creature gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Chandra's Embercat

{T}: Add {R}. Spend this mana only to cast an Elemental spell or a Chandra planeswalker spell.

Rite of the Raging Storm

Creatures named Lightning Rager can't attack you or planeswalkers you control.
At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager. It has trample, haste, and "At the beginning of the end step, sacrifice this creature."

Flamekin Harbinger

When Flamekin Harbinger enters, you may search your library for an Elemental card, reveal it, then shuffle and put that card on top.

Chandra, Novice Pyromancer

+1: Elementals you control get +2/+0 until end of turn.
−1: Add {R}{R}.
−2: Chandra, Novice Pyromancer deals 2 damage to any target.

Smokebraider

{T}: Add two mana in any combination of colors. Spend this mana only to cast Elemental spells or activate abilities of Elementals.

Firecat Blitz

Create X 1/1 red Elemental Cat creature tokens with haste. Exile them at the beginning of the next end step.
Flashback—{R}{R}, Sacrifice X Mountains. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flickerwisp

Flying
When Flickerwisp enters, exile another target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Igneous Pouncer

Haste
Swampcycling {2}, mountaincycling {2} ({2}, Discard this card: Search your library for a Swamp or Mountain card, reveal it, put it into your hand, then shuffle.)

Molten Birth

Create two 1/1 red Elemental creature tokens, then flip a coin. If you win the flip, return Molten Birth to its owner's hand.

Fertilid

Fertilid enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Caterwauling Boggart

Goblins you control and Elementals you control have menace. (They can't be blocked except by two or more creatures.)

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.)

Embodiment of Spring

{1}{G}, {T}, Sacrifice Embodiment of Spring: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Fusion Elemental

Risen Reef

Whenever Risen Reef or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.