Gift of Strength

Target creature gets +3/+3 and gains reach until end of turn.

Vorstclaw

Overcome

Creatures you control get +2/+2 and gain trample until end of turn.

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.

Bounding Wolf

Mountain

Ivy Elemental

Ivy Elemental enters the battlefield with X +1/+1 counters on it.

Rugged Highlands

Rugged Highlands enters the battlefield tapped.
When Rugged Highlands enters the battlefield, you gain 1 life.
{T}: Add {R} or {G}.

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.

Forest

Chandra's Embercat

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

Scampering Scorcher

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

Grumgully, the Generous

Each other non-Human creature you control enters the battlefield with an additional +1/+1 counter on it.

Overgrowth Elemental

When Overgrowth Elemental enters the battlefield, put a +1/+1 counter on another target Elemental you control.
Whenever another creature you control dies, you gain 1 life. If that creature was an Elemental, put a +1/+1 counter on Overgrowth Elemental.