Devoted Crop-Mate

You may exert this creature as it attacks. When you do, return target creature card with mana value 2 or less from your graveyard to the battlefield. (An exerted creature won't untap during your next untap step.)

Champion of Rhonas

You may exert this creature as it attacks. When you do, you may put a creature card from your hand onto the battlefield. (An exerted creature won't untap during your next untap step.)

Glorybringer

Flying, haste
You may exert this creature as it attacks. When you do, it deals 4 damage to target non-Dragon creature an opponent controls. (An exerted creature won't untap during your next untap step.)

Anep, Vizier of Hazoret

Trample
You may exert Anep as it attacks. When you do, exile the top two cards of your library. Until the end of your next turn, you may play those cards. (An exerted creature won't untap during your next untap step.)

Clockwork Droid

You may exert this creature as it attacks. When you do, it can't be blocked this turn and you scry 1. (An exerted creature won't untap during your next untap step. To scry 1, look at the top card of your library. You may put that card on the bottom.)

Ahn-Crop Champion

You may exert this creature as it attacks. When you do, untap all other creatures you control. (An exerted creature won't untap during your next untap step.)

Emberhorn Minotaur

You may exert this creature as it attacks. When you do, it gets +1/+1 and gains menace until end of turn. (An exerted creature won't untap during your next untap step. A creature with menace can't be blocked except by two or more creatures.)

Rhonas's Stalwart

You may exert this creature as it attacks. When you do, it gets +1/+1 until end of turn and can't be blocked by creatures with power 2 or less this turn. (An exerted creature won't untap during your next untap step.)

Watchful Naga

You may exert this creature as it attacks. When you do, draw a card. (An exerted creature won't untap during your next untap step.)

Glory-Bound Initiate

You may exert this creature as it attacks. When you do, it gets +1/+3 and gains lifelink until end of turn. (An exerted creature won't untap during your next untap step.)

Trueheart Twins

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, creatures you control get +1/+0 until end of turn.

Oketra's Avenger

You may exert this creature as it attacks. When you do, prevent all combat damage that would be dealt to it this turn. (An exerted creature won't untap during your next untap step.)

Nef-Crop Entangler

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
You may exert this creature as it attacks. When you do, it gets +1/+2 until end of turn. (An exerted creature won't untap during your next untap step.)

Hooded Brawler

You may exert this creature as it attacks. When you do, it gets +2/+2 until end of turn. (An exerted creature won't untap during your next untap step.)

Khenra Scrapper

Menace
You may exert this creature as it attacks. When you do, it gets +2/+0 until end of turn. (An exerted creature won't untap during your next untap step.)

Hydra Trainer

You may exert this creature as it attacks. When you do, target creature gets +X/+X until end of turn, where X is the number of counters on permanents you control. (An exerted creature won't untap during your next untap step.)
{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

Bitterblade Warrior

You may exert this creature as it attacks. When you do, it gets +1/+0 and gains deathtouch until end of turn. (An exerted creature won't untap during your next untap step.)

Rohirrim Chargers

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, reveal cards from the top of your library until you reveal an Equipment card. Put that card onto the battlefield attached to that creature, then put the rest on the bottom of your library in a random order.

Combat Celebrant

If this creature hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Battlefield Scavenger

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, you may discard a card. If you do, draw a card.

Sandstorm Crasher

Trample
You may exert this creature as it attacks. When you do, create a tapped and attacking token that's a copy of target creature you control. Sacrifice the token at the beginning of the next end step. (An exerted creature won't untap during your next untap step.)

Tah-Crop Elite

Flying
You may exert this creature as it attacks. When you do, creatures you control get +1/+1 until end of turn. (An exerted creature won't untap during your next untap step.)

Jetmir, Nexus of Revels

Creatures you control get +1/+0 and have vigilance as long as you control three or more creatures.
Creatures you control also get +1/+0 and have trample as long as you control six or more creatures.
Creatures you control also get +1/+0 and have double strike as long as you control nine or more creatures.

Rhet-Crop Spearmaster

You may exert this creature as it attacks. When you do, it gets +1/+0 and gains first strike until end of turn. (An exerted creature won't untap during your next untap step.)

Vizier of the True

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, tap target creature an opponent controls.

Ahn-Crop Crasher

Haste (This creature can attack and {T} as soon as it comes under your control.)
You may exert this creature as it attacks. When you do, target creature can't block this turn. (An exerted creature won't untap during your next untap step.)

Gust Walker

You may exert this creature as it attacks. When you do, it gets +1/+1 and gains flying until end of turn. (An exerted creature won't untap during your next untap step.)

Resolute Survivors

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, this creature deals 1 damage to each opponent and you gain 1 life.