PuPu UFO

an artifact attacks — 1,243 cards in the game can cause this (PuPu UFO is one).

When PuPu UFO attacks:

1. Alibou, Ancient Witness — deals X damage
2. Bio-Asset Allocator — makes each opponent lose 1 life
3. Assaultron Dominator — puts a counter on a permanent
4. Aloy, Savior of Meridian — triggers

an artifact deals combat damage — 1,243 cards in the game can cause this (PuPu UFO is one).

When PuPu UFO deals combat damage:

1. Locutus of Borg — makes a token
2. Sharding Sphinx — makes a token
3. Antagonist Incorporator — makes a token
4. Research Thief — draws you 1 card
5. Thopter Spy Network — draws you 1 card
6. Hive Mind Coprocessor — makes you lose life
7. Pia Nalaar, Chief Mechanic — puts a counter on a permanent you control
8. Automated Assembly Line — triggers

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

a nontoken artifact deals combat damage — 1,243 cards in the game can cause this (PuPu UFO is one).

1. Virulent Silencer — When PuPu UFO deals combat damage, Virulent Silencer puts 2 counters on a permanent

a land enters the battlefield — 1,560 cards in the game can cause this (PuPu UFO is one).

When a land enters thanks to PuPu UFO:

1. Primeval Bounty — gains you 3 life
2. Toph, Earthbending Master — puts a counter on a permanent
3. Dancing from Dark to Dawn — makes a token
4. Emeria Shepherd — brings a card back
5. Quest for the Necropolis — puts a quest counter on itself
6. Soul Stair Expedition — puts a quest counter on itself
7. Nissa of Shadowed Boughs — puts counters on a permanent
8. Thranduil, Sindarin Liege // Silvan Rally — makes a token
9. Silvan Reveler — returns itself from the graveyard
10. Floral Evoker — puts a +1/+1 counter on itself

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

an artifact is cast — 3,683 cards in the game can cause this (PuPu UFO is one).

When PuPu UFO is cast:

1. Mendicant Core, Guidelight — copies a spell
2. Sai, Master Thopterist — makes a token
3. Ravenous Robots — makes a token
4. Pinnacle Emissary — makes a token
5. Mirrodin Besieged — makes a token
6. Poetic Ingenuity — makes a token
7. Digsite Engineer — makes a token
8. Myrsmith — makes a token
9. Riddlesmith — draws you 1 card
10. Dr. Madison Li — puts a counter on a permanent you control

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

a nontoken artifact enters the battlefield — 3,768 cards in the game can cause this (PuPu UFO is one).

When PuPu UFO enters:

1. Ultron, Artificial Malevolence — makes a token
2. The Prydwen, Steel Flagship — makes a token
3. Conquest Mission — puts a quest counter on itself
4. Surge Conductor — proliferates
5. Replication Specialist — makes a token
6. Weapons Manufacturing — makes a token
7. Mirrorworks — makes a token

an artifact enters the battlefield — 4,643 cards in the game can cause this (PuPu UFO is one).

When PuPu UFO enters:

1. Transplant Theorist — draws you 1 card
2. Elvish Archivist — puts 2 +1/+1 counters on itself
3. Golbez, Crystal Collector — surveils
4. Sludge Strider — makes a player lose 1 life
5. Underhanded Designs — makes each opponent lose 1 life
6. Mechan Assembler — makes a token
7. Glassdust Hulk — gets +1/+1
8. Rook Turret — draws you 1 card
9. Hedron Detonator — deals 1 damage
10. Pactdoll Terror — makes each opponent lose 1 life

56 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 (PuPu UFO is one).

When PuPu UFO attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Temmet, Naktamun's Will — draws you 1 card
3. Invisible Woman — triggers
4. Caesar, Legion's Emperor — sacrifices a creature
5. Guide of Souls — triggers

132 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 (PuPu UFO is one).

1. Adaptive Omnitool — When PuPu UFO attacks, Adaptive Omnitool searches a library

198 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 (PuPu UFO is one).

When PuPu UFO enters:

1. Pollywog Prodigy — puts a counter on itself
2. Slash, Reptile Rampager — deals 2 damage
3. Ray Fillet, Wave Warrior — puts a counter on itself

348 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 (PuPu UFO is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When PuPu UFO enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

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