Thraben Watcher

an Angel enters the battlefield — 354 cards in the game can cause this (Thraben Watcher is one).

When Thraben Watcher enters:

1. Bishop of Wings — gains you 4 life
2. Youthful Valkyrie — puts a +1/+1 counter on itself
3. Seraph Sanctuary — gains you 1 life
4. Righteous Valkyrie — gains you that creature's toughness life

anything attacks — 17,934 cards in the game can cause this (Thraben Watcher is one).

When Thraben Watcher 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

489 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 (Thraben Watcher is one).

When Thraben Watcher 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. Saw — sacrifices a creature
7. Gisa's Favorite Shovel — makes an opponent sacrifice a creature
8. Ultima Weapon — kills a creature an opponent controls
9. Path of Mettle // Metzali, Tower of Triumph — triggers
10. Total War — kills a creature

843 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 (Thraben Watcher is one).

When Thraben Watcher blocks:

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

131 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 (Thraben Watcher is one).

When Thraben Watcher attacks:

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

a creature it boosts — 19,392 cards in the game can cause this (Thraben Watcher is one).

Thraben Watcher gives:

1. Pollywog Prodigy — bigger stats
2. Havengul Lich — bigger stats
3. Saheeli, Radiant Creator — bigger stats
4. Captain Jean-Luc Picard — bigger stats
5. Windrider Wizard — bigger stats
6. Master of Winds — bigger stats
7. Sokka, Bold Boomeranger — bigger stats
8. Rockslide Sorcerer — bigger stats
9. Umara Wizard // Umara Skyfalls — bigger stats
10. Alania, Divergent Storm — bigger stats

19,381 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 (Thraben Watcher is one).

When Thraben Watcher enters:

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

3,030 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 (Thraben Watcher is one).

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

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