Ur-Drago

hits creature — 881 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

1. Jalira, Master Polymorphist — Jalira, Master Polymorphist can put Ur-Drago onto the battlefield from your library
2. Polymorph — Polymorph can put Ur-Drago onto the battlefield from your library
3. Proteus Staff — Proteus Staff can put Ur-Drago onto the battlefield from your library
4. Synthetic Destiny — Synthetic Destiny can put Ur-Drago onto the battlefield from your library
5. Mass Polymorph — Mass Polymorph can put Ur-Drago onto the battlefield from your library

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

a creature attacks — 6,258 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

When Ur-Drago attacks:

1. Adaptive Omnitool — searches a library
2. Kindred Discovery — draws you 1 card
3. Chorale of the Void — brings a card back
4. Screaming Swarm — mills a card
5. Imperious Mindbreaker — mills a card
6. Staff of Titania — 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. Throwing Knife — sacrifices itself

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

anything attacks — 6,258 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

When Ur-Drago attacks:

1. Grim Javelineer — gives +1/+0
2. ED-E, Lonesome Eyebot — puts a quest counter on itself
3. Fire Navy Trebuchet — makes a token
4. Madame Web, Clairvoyant — mills a card
5. Dimir Strandcatcher — surveils
6. Stensian Sanguinist // Exsanguinate — grants deathtouch
7. Rev, Tithe Extractor — grants deathtouch
8. Gossip's Talent — triggers
9. Krydle of Baldur's Gate — triggers
10. Alora, Merry Thief — triggers

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

a creature blocks — 6,258 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

When Ur-Drago blocks:

1. Mage Hunters' Onslaught — makes a player lose 1 life
2. Barrow-Blade — strips abilities
3. Dead-Iron Sledge — kills a creature
4. Dwindle — kills a creature

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

a creature deals combat damage — 6,258 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

1. Hive Mind Coprocessor — When Ur-Drago deals combat damage, Hive Mind Coprocessor makes you lose life

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

a creature is cast — 6,287 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

When Ur-Drago is cast:

1. Endrek Sahr, Master Breeder — makes that spell's mana value tokens
2. Oketra's Monument — makes a token
3. Kozilek's Unsealing — draws you 3 cards
4. The Clone Saga — copies a spell
5. Customs Depot — draws you 1 card
6. Skittering Horror — sacrifices itself
7. Skittering Skirge — sacrifices itself
8. Skittering Monstrosity — sacrifices itself
9. Hazoret's Monument — draws and discards
10. Aether Barrier — makes a player sacrifice a permanent

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

a nontoken creature enters the battlefield — 6,508 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

When Ur-Drago enters:

1. Arni, Humble Scribe — untaps itself
2. Minion Reflector — makes a token
3. Overburden — triggers

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

a creature enters the battlefield — 6,953 cards in Ur-Drago's colors can cause this (Ur-Drago is one).

When Ur-Drago enters:

1. Ray Fillet, Wave Warrior — puts a counter on itself
2. Pollywog Prodigy — puts a counter on itself
3. Ayara, First of Locthwain — makes each opponent lose 1 life
4. Blasting Station — untaps itself
5. Sage of the Falls — draws you 1 card
6. Bloodline Pretender — puts a +1/+1 counter on itself
7. Sage's Row Denizen — mills a card
8. Monkey Cage — sacrifices itself
9. Tainted Aether — makes a player sacrifice a creature or land
10. Lethal Vapors — kills it

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