Merchant of Many Hats

an Ally deals combat damage — 265 cards in the game can cause this (Merchant of Many Hats is one).

1. Invasion Tactics — When Merchant of Many Hats deals combat damage, Invasion Tactics draws you 1 card

an Ally enters the battlefield — 285 cards in the game can cause this (Merchant of Many Hats is one).

When Merchant of Many Hats enters:

1. Turntimber Ranger — makes a token
2. Grovetender Druids — makes a token
3. Halimar Excavator — mills a card
4. Kalastria Healer — makes each opponent lose 1 life
5. South Pole Voyager — gains you 1 life
6. Ondu Cleric — gains you life
7. Tuktuk Grunts — puts a +1/+1 counter on itself
8. Sokka and Suki — triggers
9. Tuktuk Scrapper — kills an artifact an opponent controls
10. Bala Ged Thief — triggers

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

a creature leaves a graveyard — 1,302 cards in the game can cause this (Merchant of Many Hats is one).

When Merchant of Many Hats leaves a graveyard:

1. Grim Reaper's Scythe — makes a token
2. Syr Konrad, the Grim — deals 1 damage
3. Cyan, Vengeful Samurai — puts a +1/+1 counter on itself
4. Along the Crooked Way — puts a counter on a Goblin or Army
5. Skeleton Crew — makes a token
6. Desecrated Tomb — makes a token
7. Chalk Outline — makes a token
8. Insidious Roots — makes a token
9. Undead Hand Ninja — makes each opponent lose 1 life
10. Erebos's Titan — triggers

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

anything leaves a graveyard — 2,503 cards in the game can cause this (Merchant of Many Hats is one).

When Merchant of Many Hats leaves a graveyard:

1. Blastoneuron — makes each opponent lose 1 life
2. Defiled Crypt // Cadaver Lab — makes a token
3. Teval, the Balanced Scale — makes a token
4. Hologram Stalker — makes a token
5. Tormod, the Desecrator — makes a token
6. Quintorius, Field Historian — makes a token
7. Garrison Excavator — makes a token
8. Amzu, Swarm's Hunger — makes a token
9. Kirol, History Buff // Pack a Punch — becomes prepared
10. Teval's Judgment — triggers

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

a Human enters the battlefield — 4,639 cards in the game can cause this (Merchant of Many Hats is one).

When Merchant of Many Hats enters:

1. General Kudro of Drannith — hits a graveyard
2. Heronblade Elite — puts a +1/+1 counter on itself
3. Kyler, Sigardian Emissary — puts a +1/+1 counter on itself
4. Thalia's Lieutenant — puts a +1/+1 counter on itself
5. Champion of the Parish — puts a +1/+1 counter on itself
6. Captain of the Mists — untaps itself
7. Erkenbrand, Lord of Westfold — gives +1/+0
8. Beregond of the Guard — gives +1/+1
9. Théoden, King of Rohan — grants double strike
10. Lossarnach Captain — taps a creature an opponent controls

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

anything attacks — 17,934 cards in the game can cause this (Merchant of Many Hats is one).

When Merchant of Many Hats attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Temmet, Naktamun's Will — draws you 1 card
3. Invisible Woman — triggers
4. Caesar, Legion's Emperor — sacrifices a creature
5. Guide of Souls — triggers
6. Campsite Cuisine — sacrifices a Food
7. Gossip's Talent — triggers

115 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 (Merchant of Many Hats is one).

When Merchant of Many Hats attacks:

1. Adaptive Omnitool — searches a library
2. Anthem of Rakdos — gives +2/+0
3. Kindred Discovery — draws you 1 card
4. Saw — sacrifices a creature

187 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 (Merchant of Many Hats is one).

1. Tide of War — When Merchant of Many Hats blocks, Tide of War sacrifices a creature

27 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 (Merchant of Many Hats is one).

When Merchant of Many Hats enters:

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

344 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 (Merchant of Many Hats is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Merchant of Many Hats enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

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