Owlbear

a Bear enters the battlefield — 128 cards in the game can cause this (Owlbear is one).

1. Ayula, Queen Among Bears — When Owlbear enters, Ayula, Queen Among Bears triggers

a Bird attacks — 486 cards in the game can cause this (Owlbear is one).

When Owlbear attacks:

1. Hermes, Overseer of Elpis — scries
2. Choco, Seeker of Paradise — puts a land onto the battlefield

a Bird creature is cast — 486 cards in the game can cause this (Owlbear is one).

1. Chocobo Camp — When Owlbear is cast, it arrives with counters thanks to Chocobo Camp

1 other card cares about it too. These are the ones with the most connections.

a Bird deals combat damage — 486 cards in the game can cause this (Owlbear is one).

1. Kastral, the Windcrested — When Owlbear deals combat damage, Kastral, the Windcrested triggers

a nontoken Bird enters the battlefield — 487 cards in the game can cause this (Owlbear is one).

1. Knightfisher — When Owlbear enters, Knightfisher makes a token

a Bird enters the battlefield — 538 cards in the game can cause this (Owlbear is one).

1. Salvation Swan — When Owlbear enters, Salvation Swan flickers a creature you control

1 other card cares about it too. These are the ones with the most connections.

a card is drawn — 3,815 cards in the game can cause this (Owlbear is one).

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

When Owlbear 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

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 (Owlbear is one).

When Owlbear 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

181 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 (Owlbear is one).

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

When Owlbear attacks:

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

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

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

303 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 (Owlbear is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Owlbear 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.