Maro

an Elemental enters the battlefield — 754 cards in the game can cause this (Maro is one).

1. Champion of the Path — When Maro enters, Champion of the Path deals its power damage
2. Risen Reef — When Maro enters, Risen Reef puts a land onto the battlefield

anything attacks — 17,934 cards in the game can cause this (Maro is one).

1. Far Fortune, End Boss — When Maro attacks, Far Fortune, End Boss deals 1 damage
2. Temmet, Naktamun's Will — When Maro attacks, Temmet, Naktamun's Will draws you 1 card
3. Grim Javelineer — When Maro attacks, Grim Javelineer gives +1/+0
4. Invisible Woman — When Maro attacks, Invisible Woman triggers
5. Caesar, Legion's Emperor — When Maro attacks, Caesar, Legion's Emperor sacrifices a creature
6. Guide of Souls — When Maro attacks, Guide of Souls triggers
7. Campsite Cuisine — When Maro attacks, Campsite Cuisine sacrifices a Food
8. Gossip's Talent — When Maro attacks, Gossip's Talent triggers
9. Banon, the Returners' Leader — When Maro attacks, Banon, the Returners' Leader draws and discards
10. Toph, Earthbending Master — When Maro attacks, Toph, Earthbending Master puts a counter on a permanent

111 other cards care about it too. These are the ones with the most connections.

a creature attacks — 17,934 cards in the game can cause this (Maro is one).

1. Adaptive Omnitool — When Maro attacks, Adaptive Omnitool searches a library
2. Anthem of Rakdos — When Maro attacks, Anthem of Rakdos gives +2/+0
3. Kindred Discovery — When Maro attacks, Kindred Discovery draws you 1 card
4. Invasion of New Capenna // Holy Frazzle-Cannon — When Maro attacks, Invasion of New Capenna // Holy Frazzle-Cannon puts counters on a permanent
5. Chorale of the Void — When Maro attacks, Chorale of the Void brings a card back
6. Anim Pakal, Thousandth Moon — When Maro attacks, Anim Pakal, Thousandth Moon puts a +1/+1 counter on itself
7. Saw — When Maro attacks, Saw sacrifices a creature
8. Gisa's Favorite Shovel — When Maro attacks, Gisa's Favorite Shovel makes an opponent sacrifice a creature
9. Ultima Weapon — When Maro attacks, Ultima Weapon kills a creature an opponent controls
10. Total War — When Maro attacks, Total War kills a creature

182 other cards care about it too. These are the ones with the most connections.

a creature blocks — 17,934 cards in the game can cause this (Maro is one).

1. Mage Hunters' Onslaught — When Maro blocks, Mage Hunters' Onslaught makes a player lose 1 life
2. Carnage Gladiator — When Maro blocks, Carnage Gladiator makes a player lose 1 life
3. Barrow-Blade — When Maro blocks, Barrow-Blade strips abilities
4. Heat of Battle — When Maro blocks, Heat of Battle deals 1 damage
5. Battle Strain — When Maro blocks, Battle Strain deals 1 damage
6. Favor of the Woods — When Maro blocks, Favor of the Woods gains you 3 life
7. Tide of War — When Maro blocks, Tide of War sacrifices a creature
8. Dead-Iron Sledge — When Maro blocks, Dead-Iron Sledge kills a creature
9. Dwindle — When Maro blocks, Dwindle kills a creature
10. Shield of the Righteous — When Maro blocks, Shield of the Righteous triggers

18 other cards care about it too. These are the ones with the most connections.

a creature deals combat damage — 17,934 cards in the game can cause this (Maro is one).

When Maro deals combat damage:

1. Primo, the Unbounded — makes a token
2. Locutus of Borg — makes a token
3. Antagonist Incorporator — makes a token
4. Hive Mind Coprocessor — makes you lose life

193 other cards care about it too. These are the ones with the most connections.

a nontoken creature attacks — 17,934 cards in the game can cause this (Maro is one).

1. Mardu Ascendancy — When Maro attacks, Mardu Ascendancy makes a token
2. Basri Ket — When Maro attacks, Basri Ket makes a token
3. Militia's Pride — When Maro attacks, Militia's Pride makes a token

a creature is cast — 18,010 cards in the game can cause this (Maro is one).

1. Primeval Bounty — When Maro is cast, Primeval Bounty makes a token
2. Bloodbond March — When Maro is cast, Bloodbond March brings a card back
3. Dancing from Dark to Dawn — When Maro is cast, Dancing from Dark to Dawn puts that spell's mana value counters on a creature
4. Endrek Sahr, Master Breeder — When Maro is cast, Endrek Sahr, Master Breeder makes that spell's mana value tokens
5. Summon: Fenrir — When Maro is cast, it arrives with counters thanks to Summon: Fenrir
6. Summon: Brynhildr — When Maro is cast, Summon: Brynhildr grants haste
7. Skittering Horror — When Maro is cast, Skittering Horror sacrifices itself
8. Skittering Skirge — When Maro is cast, Skittering Skirge sacrifices itself
9. Skittering Monstrosity — When Maro is cast, Skittering Monstrosity sacrifices itself
10. Silverback Elder — When Maro is cast, Silverback Elder triggers

81 other cards care about it too. These are the ones with the most connections.

a nontoken creature enters the battlefield — 18,448 cards in the game can cause this (Maro is one).

1. Riku of Two Reflections — When Maro enters, Riku of Two Reflections makes a token
2. Samwise Gamgee — When Maro enters, Samwise Gamgee makes a token
3. Dual Nature — When Maro enters, Dual Nature makes a token
4. Angelic Sell-Sword — When Maro enters, Angelic Sell-Sword makes a token
5. Lonis, Cryptozoologist — When Maro enters, Lonis, Cryptozoologist triggers

28 other cards care about it too. These are the ones with the most connections.

a creature enters the battlefield — 19,800 cards in the game can cause this (Maro is one).

1. Slash, Reptile Rampager — When Maro enters, Slash, Reptile Rampager deals 2 damage
2. The Neutrinos — When Maro enters, The Neutrinos gets +1/+0
3. Wingnut, Bat on the Belfry — When Maro enters, Wingnut, Bat on the Belfry grants flying, haste and menace
4. Aetherstorm Roc — When Maro enters, Aetherstorm Roc puts a counter on a permanent you control
5. Raphael, Most Attitude — When Maro enters, Raphael, Most Attitude exiles a card from your library

302 other cards care about it too. These are the ones with the most connections.

anything enters the battlefield — 26,499 cards in the game can cause this (Maro is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Maro enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

40 other cards care about it too. These are the ones with the most connections.