Mild-Mannered Librarian

a Human gets a counter — 326 cards in the game can cause this (Mild-Mannered Librarian is one).

1. Cloaked Cadet — When Mild-Mannered Librarian gets a counter, Cloaked Cadet draws you 1 card

a creature gets a counter — 2,691 cards in the game can cause this (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian gets a counter:

1. Hollowmurk Siege — draws you 1 card
2. Ant-Man, Colony Commander — makes a token
3. Earth Kingdom General — gains you that much life
4. Casey Jones, Back Alley Brute — deals that much damage
5. Generous Patron — draws you 1 card
6. Shalai and Hallar — deals that much damage
7. Danny Pink — draws you 1 card
8. Enduring Scalelord — puts a +1/+1 counter on itself
9. Bold Plagiarist — puts counters on a permanent
10. Mikey & Leo, Chaos & Order — draws you 1 card

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

a card is drawn — 3,815 cards in the game can cause this (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian makes a player draw a card:

1. Temmet, Naktamun's Will — gives +1/+1
2. Niv-Mizzet, Parun — deals 1 damage
3. Aether Syphon — mills a card
4. The Locust God — makes a token
5. Starving Revenant — makes each opponent lose 1 life
6. Diviner's Wand — gets +1/+1
7. Ominous Seas — puts a foreshadow counter on itself
8. Dream Trawler — gets +1/+0
9. Iron Man, Armored Avenger — puts a counter on a creature
10. The Astonishing Ant-Man — puts a +1/+1 counter on itself

57 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 (Mild-Mannered Librarian is one).

1. All Will Be One — When Mild-Mannered Librarian gets a counter, All Will Be One deals that much damage

8 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 (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian 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 (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Grim Javelineer — gives +1/+0
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
8. Banon, the Returners' Leader — draws and discards
9. Toph, Earthbending Master — puts a counter on a permanent
10. Three Dog, Galaxy News DJ — sacrifices an Aura

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 (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian 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. Saw — sacrifices a creature
7. Gisa's Favorite Shovel — makes an opponent sacrifice a creature
8. Ultima Weapon — kills a creature an opponent controls

184 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 (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian blocks:

1. Tide of War — sacrifices a creature
2. Dead-Iron Sledge — kills a creature

26 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 (Mild-Mannered Librarian is one).

When Mild-Mannered Librarian enters:

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

306 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 (Mild-Mannered Librarian is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Mild-Mannered Librarian enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

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