Necropanther

a Nightmare enters the battlefield — 151 cards in the game can cause this (Necropanther is one).

1. Umbris, Fear Manifest — When Necropanther enters, Umbris, Fear Manifest exiles a card from an opponent's library

a Cat deals combat damage — 395 cards in the game can cause this (Necropanther is one).

1. Feline Sovereign — When Necropanther deals combat damage, Feline Sovereign kills an artifact or enchantment an opponent controls

a Cat attacks — 395 cards in the game can cause this (Necropanther is one).

1. Arahbo, Roar of the World — When Necropanther attacks, Arahbo, Roar of the World grants trample

a nontoken Cat enters the battlefield — 396 cards in the game can cause this (Necropanther is one).

1. Arahbo, the First Fang — When Necropanther enters, Arahbo, the First Fang makes a token

a Cat enters the battlefield — 414 cards in the game can cause this (Necropanther is one).

When Necropanther enters:

1. Qasali Slingers — kills an artifact or enchantment an opponent controls
2. Kemba, Kha Enduring — triggers

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

When Necropanther 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. Rot Farm Mortipede — gets +1/+0

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 (Necropanther is one).

When Necropanther 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.

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

When Necropanther 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

112 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 (Necropanther is one).

When Necropanther 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. Anim Pakal, Thousandth Moon — puts a +1/+1 counter on itself
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 (Necropanther is one).

When Necropanther blocks:

1. Mage Hunters' Onslaught — makes a player lose 1 life
2. Tide of War — sacrifices a creature
3. Dead-Iron Sledge — kills a creature
4. Dwindle — kills a creature

24 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 (Necropanther is one).

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

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 (Necropanther is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Necropanther enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself
2. Ivora, Insatiable Heir — When Ivora, Insatiable Heir enters thanks to Necropanther, it makes a token
3. Dogmeat, Ever Loyal — When Dogmeat, Ever Loyal enters thanks to Necropanther, it mills a card

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