Oculus

a Phyrexian attacks — 495 cards in the game can cause this (Oculus is one).

1. Vulpine Harvester — When Oculus attacks, Vulpine Harvester brings a card back

a nontoken Phyrexian enters the battlefield — 496 cards in the game can cause this (Oculus is one).

1. Darksteel Splicer — When Oculus enters, Darksteel Splicer makes a token

a Phyrexian enters the battlefield — 524 cards in the game can cause this (Oculus is one).

1. Essence of Orthodoxy — When Oculus enters, Essence of Orthodoxy puts a counter on a permanent

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

When Oculus 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 (Oculus is one).

1. Far Fortune, End Boss — When Oculus attacks, Far Fortune, End Boss deals 1 damage
2. Grim Javelineer — When Oculus attacks, Grim Javelineer gives +1/+0
3. Invisible Woman — When Oculus attacks, Invisible Woman triggers
4. Caesar, Legion's Emperor — When Oculus attacks, Caesar, Legion's Emperor sacrifices a creature
5. Guide of Souls — When Oculus attacks, Guide of Souls triggers
6. Campsite Cuisine — When Oculus attacks, Campsite Cuisine sacrifices a Food
7. Gossip's Talent — When Oculus attacks, Gossip's Talent triggers
8. Banon, the Returners' Leader — When Oculus attacks, Banon, the Returners' Leader draws and discards
9. Toph, Earthbending Master — When Oculus attacks, Toph, Earthbending Master puts a counter on a permanent
10. Three Dog, Galaxy News DJ — When Oculus attacks, 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 (Oculus is one).

1. Adaptive Omnitool — When Oculus attacks, Adaptive Omnitool searches a library
2. Anthem of Rakdos — When Oculus attacks, Anthem of Rakdos gives +2/+0
3. Kindred Discovery — When Oculus attacks, Kindred Discovery draws you 1 card
4. Invasion of New Capenna // Holy Frazzle-Cannon — When Oculus attacks, Invasion of New Capenna // Holy Frazzle-Cannon puts counters on a permanent
5. Chorale of the Void — When Oculus attacks, Chorale of the Void brings a card back
6. Anim Pakal, Thousandth Moon — When Oculus attacks, Anim Pakal, Thousandth Moon puts a +1/+1 counter on itself
7. Saw — When Oculus attacks, Saw sacrifices a creature
8. Gisa's Favorite Shovel — When Oculus attacks, Gisa's Favorite Shovel makes an opponent sacrifice a creature
9. Ultima Weapon — When Oculus attacks, Ultima Weapon kills a creature an opponent controls
10. Total War — When Oculus attacks, 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 (Oculus is one).

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

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

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

1. Locutus of Borg — When Oculus deals combat damage, Locutus of Borg makes a token

196 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 (Oculus is one).

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

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