"Capthreecorn" enters the battlefield with X +1/+1 counters on it.
: Put a +1/+1 counter on "Capthreecorn". You may reselect which player "Capthreecorn" is attacking. Only a player being attacked by "Capthreecorn" may activate this ability, and only during the declare attackers step. (It can't attack its controller.)

Delve (Each card you exile from your graveyard while casting this spell pays for .)
Flying
Whenever "Eater of Clouds" attacks, you may put an instant or sorcery exiled by "Eater of Clouds" into your hand.

When Amphin Mutineer enters the battlefield, exile up to one target non-Salamander creature. That creature's controller creates a 4/3 blue Salamander Warrior creature token.
Encore (, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Flash
When Blitz Leech enters the battlefield, target creature an opponent controls gets -2/-2 until end of turn. Remove all counters from that creature.

Boot Nipper enters the battlefield with your choice of a deathtouch counter or a lifelink counter on it.

Capricopian enters the battlefield with X +1/+1 counters on it.
: Put a +1/+1 counter on Capricopian, then you may reselect which player Capricopian is attacking. Only the player Capricopian is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

Carrion Grub gets +X/+0, where X is the greatest power among creature cards in your graveyard.
When Carrion Grub enters the battlefield, mill four cards. (Put the top four cards of your library into your graveyard.)

(Theme color: )

Vigilance, reach, trample
Whenever Elder Gargaroth attacks or blocks, choose one —
• Create a 3/3 green Beast creature token.
• You gain 3 life.
• Draw a card.

Delve (Each card you exile from your graveyard while casting this spell pays for .)
Flying
Whenever Ethereal Forager attacks, you may return an instant or sorcery card exiled with Ethereal Forager to its owner's hand.

Vigilance, trample
When Feasting Troll King enters the battlefield, if you cast it from your hand, create three Food tokens. (They're artifacts with ", , Sacrifice this artifact: You gain 3 life.")
Sacrifice three Foods: Return Feasting Troll King from your graveyard to the battlefield. Activate this ability only during your turn.

Fertilid enters the battlefield with two +1/+1 counters on it.
, 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 their library.

Trample
When Fierce Witchstalker enters the battlefield, create a Food token. (It's an artifact with ", , Sacrifice this artifact: You gain 3 life.")

Return target permanent card from your graveyard to your hand. If a creature died this turn, create two 1/1 green Saproling creature tokens.

Adamant — If at least three green mana was spent to cast this spell, Garenbrig Paladin enters the battlefield with a +1/+1 counter on it.
Garenbrig Paladin can't be blocked by creatures with power 2 or less.

Hangarback Walker enters the battlefield with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
, : Put a +1/+1 counter on Hangarback Walker.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
, Sacrifice another creature: Put a +1/+1 counter on Hobblefiend.

Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying, trample
Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand.

Whenever you cast your first instant spell each turn, if Kalamax, the Stormsire is tapped, copy that spell. You may choose new targets for the copy.
Whenever you copy an instant spell, put a +1/+1 counter on Kalamax.

Choose one. If you control a commander as you cast this spell, you may choose both.
• Until end of turn, any number of target lands you control become 1/1 Elemental creatures with vigilance, indestructible, and haste. They're still lands.
• Choose target creature you don't control. Each creature you control deals damage equal to its power to that creature.