Greenseeker

an Elf attacks — 723 cards in the game can cause this (Greenseeker is one).

When Greenseeker attacks:

1. Celeborn the Wise — scries
2. Tyvar the Bellicose — grants deathtouch
3. Harald Unites the Elves — shrinks a creature by -1/-1
4. Arboreal Alliance — triggers

a nontoken Elf enters the battlefield — 728 cards in the game can cause this (Greenseeker is one).

1. Wirewood Hivemaster — When Greenseeker enters, Wirewood Hivemaster makes a token

an Elf enters the battlefield — 752 cards in the game can cause this (Greenseeker is one).

When Greenseeker enters:

1. Wolverine Riders — gains you its toughness life
2. Elvish Warmaster — makes a token
3. Elvish Vanguard — puts a +1/+1 counter on itself
4. Marwyn, the Nurturer — puts a +1/+1 counter on itself
5. Woodland Weavemaster — gets +1/+1
6. High Perfect Morcant — puts a counter on a permanent an opponent controls
7. Maralen, Fae Ascendant — exiles a card from an opponent's library

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

a card is discarded — 2,042 cards in the game can cause this (Greenseeker is one).

When Greenseeker makes a player discard a card:

1. Ivora, Insatiable Heir — puts a +1/+1 counter on itself
2. Cool but Rude — deals 2 damage
3. Containment Construct — brings a card back
4. Moonstone, Harsh Mistress — brings a card back
5. Lazotep Chancellor — puts 2 counters on a Zombie or Army
6. Magmakin Artillerist — deals that much damage
7. Inti, Seneschal of the Sun — exiles a card from your library
8. Pitchstone Wall — sacrifices itself
9. Currency Converter — exiles it
10. Hostile Investigator — triggers

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

a card in a graveyard — 7,589 cards in the game can cause this (Greenseeker is one).

1. Samwise Gamgee — Greenseeker puts cards into the graveyard that Samwise Gamgee can bring back
2. Bloodbond March — Greenseeker puts cards into the graveyard that Bloodbond March can bring back
3. Thor, God of Thunder — Greenseeker puts cards into the graveyard that Thor, God of Thunder can bring back
4. Gale, Waterdeep Prodigy — Greenseeker puts cards into the graveyard that Gale, Waterdeep Prodigy can bring back
5. Harness the Storm — Greenseeker puts cards into the graveyard that Harness the Storm can bring back
6. Transplant Theorist — Greenseeker puts cards into the graveyard that Transplant Theorist can bring back
7. Heart-Shaped Herb — Greenseeker puts cards into the graveyard that Heart-Shaped Herb can bring back
8. Wayward Angel — Greenseeker fills your graveyard toward the 7 or more cards Wayward Angel needs
9. Rescue from the Underworld — Greenseeker puts cards into the graveyard that Rescue from the Underworld can bring back
10. Victimize — Greenseeker puts cards into the graveyard that Victimize can bring back

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

anything goes to a graveyard — 7,589 cards in the game can cause this (Greenseeker is one).

When a card hits the graveyard thanks to Greenseeker:

1. Quest for Ancient Secrets — puts a quest counter on itself
2. Planar Void — hits a graveyard
3. Measure of Wickedness — gives an opponent control of itself
4. Energy Field — sacrifices itself

7 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 (Greenseeker is one).

When Greenseeker 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

121 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 (Greenseeker is one).

When Greenseeker 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. Saw — sacrifices a creature

194 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 (Greenseeker is one).

1. Tide of War — When Greenseeker blocks, Tide of War sacrifices a creature

29 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 (Greenseeker is one).

When Greenseeker enters:

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

345 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 (Greenseeker is one).

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

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