Madame Hydra

a Villain deals combat damage — 133 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

1. Stilt-Man, Towering Terror — When Madame Hydra deals combat damage, Stilt-Man, Towering Terror triggers

a Villain enters the battlefield — 144 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When a Villain enters thanks to Madame Hydra:

1. Doom Reigns Supreme — makes each opponent lose 1 life
2. Crossbones, Malicious Mercenary — puts a +1/+1 counter on itself
3. Yellowjacket, Heartless Marauder — gets +1/+0
4. Swordsman, Sharp Scoundrel — triggers
5. Baron Strucker, HYDRA Overlord — draws and discards

provide a creature to sacrifice — 869 cards in Madame Hydra's colors can cause this.

1. Kethek, Crucible Goliath — Madame Hydra makes fodder for Kethek, Crucible Goliath
2. Industrial Advancement — Madame Hydra makes fodder for Industrial Advancement
3. Divergent Transformations — Madame Hydra makes fodder for Divergent Transformations
4. Transmogrify — Madame Hydra makes fodder for Transmogrify

865 other cards cause it too. These are the ones with the most connections.

a token is created — 1,303 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra makes a Villain token:

1. Idol of Oblivion — draws you 1 card
2. Mirkwood Bats — makes each opponent lose 1 life

a Human enters the battlefield — 1,280 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra enters:

1. Erkenbrand, Lord of Westfold — gives +1/+0
2. Vigilante Justice — deals 1 damage

anything attacks — 6,499 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Grim Javelineer — gives +1/+0
3. ED-E, Lonesome Eyebot — puts a quest counter on itself
4. Fire Navy Trebuchet — makes a token
5. Misty Mountains Raider — puts 2 counters on a Goblin or Army
6. Razorkin Hordecaller — makes a token
7. Inti, Seneschal of the Sun — triggers
8. Gut, True Soul Zealot — sacrifices a creature or artifact
9. Cool but Rude — draws and discards
10. Swashbuckler Extraordinaire — sacrifices a Treasure

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

a creature attacks — 6,499 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra attacks:

1. Adaptive Omnitool — searches a library
2. Anthem of Rakdos — gives +2/+0
3. Chorale of the Void — brings a card back
4. Ingris Stingerquill — deals 1 damage
5. Staff of Titania — makes a token
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. Total War — kills a creature
10. The Spear of Leonidas — triggers

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

a creature blocks — 6,499 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra 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. Tide of War — sacrifices a creature
7. Dead-Iron Sledge — kills a creature

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

a creature deals combat damage — 6,499 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

1. Hive Mind Coprocessor — When Madame Hydra deals combat damage, Hive Mind Coprocessor makes you lose life

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

a creature is cast — 6,529 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra is cast:

1. Endrek Sahr, Master Breeder — makes that spell's mana value tokens
2. Summon: Brynhildr — grants haste
3. Oketra's Monument — makes a token
4. Bontu's Monument — makes each opponent lose 1 life
5. Vanquisher's Banner — 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. Kefnet's Monument — triggers

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

a nontoken creature enters the battlefield — 6,736 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

When Madame Hydra enters:

1. Minion Reflector — makes a token
2. Molten Echoes — makes a token
3. Flameshadow Conjuring — makes a token
4. Mirror March — flips a coin

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

a creature enters the battlefield — 7,209 cards in Madame Hydra's colors can cause this (Madame Hydra is one).

1. Slash, Reptile Rampager — When a Villain enters thanks to Madame Hydra, Slash, Reptile Rampager deals 2 damage
2. Gimli of the Glittering Caves — When Madame Hydra enters, Gimli of the Glittering Caves puts counters on a permanent
3. Wingnut, Bat on the Belfry — When a Villain enters thanks to Madame Hydra, Wingnut, Bat on the Belfry grants flying, haste and menace
4. Ayara, First of Locthwain — When a Villain enters thanks to Madame Hydra, Ayara, First of Locthwain makes each opponent lose 1 life
5. Blasting Station — When a Villain enters thanks to Madame Hydra, Blasting Station untaps itself
6. Raphael, Most Attitude — When a Villain enters thanks to Madame Hydra, Raphael, Most Attitude exiles a card from your library
7. Mogg Bombers — When a Villain enters thanks to Madame Hydra, Mogg Bombers sacrifices itself
8. Flame-Kin War Scout — When a Villain enters thanks to Madame Hydra, Flame-Kin War Scout sacrifices itself

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