Sludge Monster

a Horror deals combat damage — 382 cards in the game can cause this (Sludge Monster is one).

1. Captain N'ghathrod — When Sludge Monster deals combat damage, Captain N'ghathrod mills a card

a creature gets a counter — 2,691 cards in the game can cause this (Sludge Monster is one).

When a creature gets a counter thanks to Sludge Monster:

1. Hollowmurk Siege — draws you 1 card
2. Generous Patron — draws you 1 card
3. Danny Pink — draws you 1 card
4. Bold Plagiarist — puts counters on a permanent
5. Mikey & Leo, Chaos & Order — draws you 1 card
6. Kros, Defense Contractor — triggers
7. Rikku, Resourceful Guardian — triggers

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

anything gets a counter — 4,415 cards in the game can cause this (Sludge Monster is one).

1. All Will Be One — When a creature gets a counter thanks to Sludge Monster, All Will Be One deals that much damage

8 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 (Sludge Monster is one).

When Sludge Monster attacks:

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

113 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 (Sludge Monster is one).

When Sludge Monster attacks:

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

180 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 (Sludge Monster is one).

When Sludge Monster blocks:

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

18 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 (Sludge Monster is one).

When Sludge Monster attacks:

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

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

When Sludge Monster deals combat damage:

1. Locutus of Borg — makes a token
2. Antagonist Incorporator — makes a token
3. Hive Mind Coprocessor — makes you lose life

194 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 (Sludge Monster is one).

When Sludge Monster enters:

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

298 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 (Sludge Monster is one).

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

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