Creatures you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
{1}{G}: Regenerate target creature.
{4}{G}{G}
Bounty of Might
Instant
Target creature gets +3/+3 until end of turn.
Target creature gets +3/+3 until end of turn.
Target creature gets +3/+3 until end of turn.
{5}{G}
Briar Hydra
Creature - Plant Hydra
Trample
Domain -- Whenever Briar Hydra deals combat damage to a player, put X +1/+1 counters on target creature you control, where X is the number of basic land types among lands you control.
6 /
6
{2}{G}
Cultivate
Sorcery
Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.
{3}
Decanter of Endless Water
Artifact
You have no maximum hand size.
{T}: Add one mana of any color.
--
Desert
Land - Desert
{T}: Add {C}.
{T}: Desert deals 1 damage to target attacking creature. Activate only during the end of combat step.
--
Desert of the Indomitable
Land - Desert
Desert of the Indomitable enters the battlefield tapped.
{T}: Add {G}.
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)
--
Drannith Ruins
Land
{T}: Add {C}.
{2}, {T}: Put two +1/+1 counters on target non-Human creature that entered the battlefield this turn.
{2}
Emerald Medallion
Artifact
Green spells you cast cost {1} less to cast.
{1}{G}
Evolution Charm
Instant
Choose one --
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Return target creature card from your graveyard to your hand.
• Target creature gains flying until end of turn.
--
Forest
Basic Land - Forest
({T}: Add {G}.)
{3}{G}{G}{G}
Gargos, Vicious Watcher
Legendary Creature - Hydra
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.
8 /
7
{X}{G}{G}
Genesis Hydra
Creature - Plant Hydra
When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters the battlefield with X +1/+1 counters on it.
0 /
0
--
Hall of Oracles
Land
{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.
{3}
Herald's Horn
Artifact
As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.
{X}{G}{G}
Hooded Hydra
Creature - Snake Hydra
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.
0 /
0
{X}{G}
Hungering Hydra
Creature - Hydra
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.)
0 /
0
{4}{G}{G}
Hydra Broodmaster
Creature - Hydra
{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.
7 /
7
{4}{G}{G}
Hydra Omnivore
Creature - Hydra
Whenever Hydra Omnivore deals combat damage to an opponent, it deals that much damage to each other opponent.
8 /
8
{2}{G}
Hydra's Growth
Enchantment - Aura
Enchant creature
When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.
{3}{G}{G}
Kalonian Hydra
Creature - 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.
0 /
0
{X}{G}{G}{G}
Lifeblood Hydra
Creature - Hydra
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.
0 /
0
{2}{G}
Managorger Hydra
Creature - Hydra
Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.
1 /
1
{X}{G}
Mistcutter Hydra
Creature - Hydra
This spell can't be countered.
Haste, protection from blue
Mistcutter Hydra enters the battlefield with X +1/+1 counters on it.
0 /
0
{2}{G}
Natural Connection
Instant
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{4}{G}{G}
Nessian Wilds Ravager
Creature - Hydra
Tribute 6 (As this creature enters the battlefield, an opponent of your choice may put six +1/+1 counters on it.)
When Nessian Wilds Ravager enters the battlefield, if tribute wasn't paid, you may have Nessian Wilds Ravager fight another target creature. (Each deals damage equal to its power to the other.)
6 /
6
{X}{X}{G}{G}
Neverwinter Hydra
Creature - Hydra
As Neverwinter Hydra enters the battlefield, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.
Trample
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
0 /
0
{4}{G}{G}
Oran-Rief Hydra
Creature - 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.
5 /
5
--
Oran-Rief, the Vastwood
Land
Oran-Rief, the Vastwood enters the battlefield tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered the battlefield this turn.
{2}{G}{G}{G}
Overrun
Sorcery
Creatures you control get +3/+3 and gain trample until end of turn.
{1}{G}
Primal Rage
Enchantment
Creatures you control have trample. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
{X}{G}{G}
Primordial Hydra
Creature - Hydra
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.
0 /
0
{X}{G}
Protean Hydra
Creature - Hydra
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.
0 /
0
{3}{G}
Rampant Rejuvenator
Creature - Plant Hydra
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.
0 /
0
{3}{G}
Ramunap Hydra
Creature - Snake Hydra
Vigilance, reach, trample
Ramunap Hydra gets +1/+1 as long as you control a Desert.
Ramunap Hydra gets +1/+1 as long as there is a Desert card in your graveyard.
3 /
3
{1}{G}
Return to Nature
Instant
Choose one --
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.
{3}
Rhonas's Monument
Legendary Artifact
Green creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.
{2}{G}
Scourge of Skola Vale
Creature - Hydra
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.
0 /
0
{X}{G}{G}
Steelbane Hydra
Creature - Turtle Hydra
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.
0 /
0
{G}
Tail Swipe
Instant
Choose target creature you control and target creature you don't control. If you cast this spell during your main phase, the creature you control gets +1/+1 until end of turn. Then those creatures fight each other. (Each deals damage equal to its power to the other.)
{1}{G}
Three Visits
Sorcery
Search your library for a Forest card, put it onto the battlefield, then shuffle.
{2}{G}{G}
Triumph of the Hordes
Sorcery
Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{4}{G}{G}
Ulvenwald Hydra
Creature - Hydra
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.
* /
*
{X}{G}{G}
Vastwood Hydra
Creature - Hydra
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.
0 /
0
{X}{G}{G}
Voracious Hydra
Creature - Hydra
Trample
Voracious Hydra enters the battlefield with X +1/+1 counters on it.
When Voracious Hydra enters the battlefield, choose one --
• Double the number of +1/+1 counters on Voracious Hydra.
• Voracious Hydra fights target creature you don't control.
0 /
1
{5}{G}
Whiptongue Hydra
Creature - Lizard Hydra
Reach
When Whiptongue Hydra enters the battlefield, destroy all creatures with flying. Put a +1/+1 counter on Whiptongue Hydra for each creature destroyed this way.