Apocalypse Hydra enters the battlefield with X +1/+1 counters on it. If X is 5 or more, it enters the battlefield with an additional X +1/+1 counters on it. {1}{R}, Remove a +1/+1 counter from Apocalypse Hydra: It deals 1 damage to any target.

Benevolent Hydra enters the battlefield with X +1/+1 counters on it. If one or more +1/+1 counters would be put on another creature you control, that many plus one +1/+1 counters are put on it instead. {T}, Remove a +1/+1 counter from Benevolent Hydra: Put a +1/+1 counter on another target creature you control.

Feral Hydra enters the battlefield with X +1/+1 counters on it. {3}: Put a +1/+1 counter on Feral Hydra. Any player may activate this ability.

Vigilance Hydra spells you cast cost {4} less to cast. Whenever a creature you control becomes the target of a spell, Gargos, Vicious Watcher fights up to one target creature you don't control.

Heroes' Bane enters the battlefield with four +1/+1 counters on it. {2}{G}{G}: Put X +1/+1 counters on Heroes' Bane, where X is its power.

Hooded Hydra enters the battlefield with X +1/+1 counters on it. When Hooded Hydra dies, create a 1/1 green Snake creature token for each +1/+1 counter on it. Morph {3}{G}{G} As Hooded Hydra is turned face up, put five +1/+1 counters on it.

Hungering Hydra enters the battlefield with X +1/+1 counters on it. Hungering Hydra can't be blocked by more than one creature. Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.) When Hydra Broodmaster becomes monstrous, create X X/X green Hydra creature tokens.

Whenever Hydra Omnivore deals combat damage to an opponent, it deals that much damage to each other opponent.

When you cast this spell, you gain half X life and draw half X cards. Round down each time. Flying, trample Hydroid Krasis enters the battlefield with X +1/+1 counters on it.

If a creature would deal combat damage to Ironscale Hydra, prevent that damage and put a +1/+1 counter on Ironscale Hydra.

Trample Kalonian Hydra enters the battlefield with four +1/+1 counters on it. Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

Trample Lifeblood Hydra enters the battlefield with X +1/+1 counters on it. When Lifeblood Hydra dies, you gain life and draw cards equal to its power.

Trample Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Trample Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.) When Polukranos, World Eater becomes monstrous, it deals X damage divided as you choose among any number of target creatures your opponents control. Each of those creatures deals damage equal to its power to Polukranos.

Primordial Hydra enters the battlefield with X +1/+1 counters on it. At the beginning of your upkeep, double the number of +1/+1 counters on Primordial Hydra. Primordial Hydra has trample as long as it has ten or more +1/+1 counters on it.

Protean Hydra enters the battlefield with X +1/+1 counters on it. If damage would be dealt to Protean Hydra, prevent that damage and remove that many +1/+1 counters from it. Whenever a +1/+1 counter is removed from Protean Hydra, put two +1/+1 counters on it at the beginning of the next end step.

Rampant Rejuvenator enters the battlefield with two +1/+1 counters on it. When Rampant Rejuvenator dies, search your library for up to X basic land cards, where X is Rampant Rejuvenator's power, put them onto the battlefield, then shuffle.

Double strike Savageborn Hydra enters the battlefield with X +1/+1 counters on it. {1}{R/G}: Put a +1/+1 counter on Savageborn Hydra. Activate only as a sorcery.

Trample Scourge of Skola Vale enters the battlefield with two +1/+1 counters on it. {T}, Sacrifice another creature: Put a number of +1/+1 counters on Scourge of Skola Vale equal to the sacrificed creature's toughness.

Flying, haste Shivan Devastator enters the battlefield with X +1/+1 counters on it.

Steelbane Hydra enters the battlefield with X +1/+1 counters on it. {2}{G}, Remove a +1/+1 counter from Steelbane Hydra: Destroy target artifact or enchantment.

Flying The Goose Mother enters the battlefield with X +1/+1 counters on it. When The Goose Mother enters the battlefield, create half X Food tokens, rounded up. Whenever The Goose Mother attacks, you may sacrifice a Food. If you do, draw a card.

Reach Ulvenwald Hydra's power and toughness are each equal to the number of lands you control. When Ulvenwald Hydra enters the battlefield, you may search your library for a land card, put it onto the battlefield tapped, then shuffle.

Vastwood Hydra enters the battlefield with X +1/+1 counters on it. When Vastwood Hydra dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra among any number of creatures you control.