Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Centaur Glade

{2}{G}{G}: Create a 3/3 green Centaur creature token.

Leaf Dancer

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)

Pheres-Band Thunderhoof

Heroic — Whenever you cast a spell that targets Pheres-Band Thunderhoof, put two +1/+1 counters on Pheres-Band Thunderhoof.

Jolrael's Centaur

Shroud (This creature can't be the target of spells or abilities.)
Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Centaur Archer

{T}: Centaur Archer deals 1 damage to target creature with flying.

Pheres-Band Tromper

Inspired — Whenever Pheres-Band Tromper becomes untapped, put a +1/+1 counter on it.

Pheres-Band Brawler

When Pheres-Band Brawler enters, it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)

Centaur Battlemaster

Heroic — Whenever you cast a spell that targets Centaur Battlemaster, put three +1/+1 counters on Centaur Battlemaster.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Pheres-Band Centaurs

Swamp

Forest

Still Life

{G}{G}: Still Life becomes a 4/3 Centaur creature in addition to its other types until end of turn.

Jund Panorama

{T}: Add {C}.
{1}, {T}, Sacrifice Jund Panorama: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.

Forcemage Advocate

{T}: Return target card from an opponent's graveyard to their hand. Put a +1/+1 counter on target creature.

Centaur Rootcaster

Whenever Centaur Rootcaster deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Skyshooter

Reach (This creature can block creatures with flying.)
{T}, Sacrifice Skyshooter: Destroy target attacking or blocking creature with flying.

Centaur Garden

{T}: Add {G}. Centaur Garden deals 1 damage to you.
Threshold — {G}, {T}, Sacrifice Centaur Garden: Target creature gets +3/+3 until end of turn. Activate only if seven or more cards are in your graveyard.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Pheres-Band Warchief

Vigilance, trample
Other Centaur creatures you control get +1/+1 and have vigilance and trample.

Centaur Chieftain

Haste
Threshold — As long as seven or more cards are in your graveyard, Centaur Chieftain has "When Centaur Chieftain enters, creatures you control get +1/+1 and gain trample until end of turn."

Prossh, Skyraider of Kher

When you cast this spell, create X 0/1 red Kobold creature tokens named Kobolds of Kher Keep, where X is the amount of mana spent to cast it.
Flying
Sacrifice another creature: Prossh, Skyraider of Kher gets +1/+0 until end of turn.

Crashing Centaur

{G}, Discard a card: Crashing Centaur gains trample until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Crashing Centaur gets +2/+2 and has shroud. (It can't be the target of spells or abilities.)

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Seton's Desire

Enchant creature
Enchanted creature gets +2/+2.
Threshold — As long as seven or more cards are in your graveyard, all creatures able to block enchanted creature do so.

Mountain

Naturalize

Phantom Centaur

Protection from black
Phantom Centaur enters with three +1/+1 counters on it.
If damage would be dealt to Phantom Centaur, prevent that damage. Remove a +1/+1 counter from Phantom Centaur.

Krosan Archer

Reach (This creature can block creatures with flying.)
{G}, Discard a card: Krosan Archer gets +0/+2 until end of turn.

Seton's Scout

Reach (This creature can block creatures with flying.)
Threshold — Seton's Scout gets +2/+2 as long as seven or more cards are in your graveyard.