Gargos, Vicious Watcher

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

Ulvenwald Hydra

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

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Selvala, Heart of the Wilds

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power.
{G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

Circle of Dreams Druid

{T}: Add {G} for each creature you control.

Urban Burgeoning

Enchant land
Enchanted land has "Untap this land during each other player's untap step."

Heroes' Bane

This creature enters with four +1/+1 counters on it.
{2}{G}{G}: Put X +1/+1 counters on this creature, where X is its power.

Wolfwillow Haven

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.
{4}{G}, Sacrifice this Aura: Create a 2/2 green Wolf creature token. Activate only during your turn.

Hydra Broodmaster

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

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Elvish Guidance

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G} for each Elf on the battlefield.

Pounce

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Kalonian Hydra

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

Invigorating Surge

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on that creature.

Ironscale Hydra

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

Hydra Omnivore

Whenever this creature deals combat damage to an opponent, it deals that much damage to each other opponent.

Ancient Animus

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Forest

Overgrowth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}{G}.

Praetor's Counsel

Return all cards from your graveyard to your hand. Exile Praetor's Counsel. You have no maximum hand size for the rest of the game.

Sylvan Might

Target creature gets +2/+2 and gains trample until end of turn.
Flashback {2}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

The Great Aurora

Each player shuffles all cards from their hand and all permanents they own into their library, then draws that many cards. Each player may put any number of land cards from their hand onto the battlefield. Exile The Great Aurora.

Elvish Mystic

Cultivate

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.

Bonds of Mortality

When this enchantment enters, draw a card.
{G}: Creatures your opponents control lose hexproof and indestructible until end of turn.

Nissa, Who Shakes the World

Whenever you tap a Forest for mana, add an additional {G}.
+1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land.
−8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Spinning Wheel Kick

Target creature you control deals damage equal to its power to each of X target creatures and/or planeswalkers.

Primal Might

Target creature you control gets +X/+X until end of turn. Then it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)

Dawn's Reflection

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional two mana in any combination of colors.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Druid of the Cowl

Sol Ring

Llanowar Elves

Llanowar Tribe

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Leaf Gilder

Llanowar Scout

{T}: You may put a land card from your hand onto the battlefield.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Nessian Wilds Ravager

Tribute 6 (As this creature enters, an opponent of your choice may put six +1/+1 counters on it.)
When this creature enters, if tribute wasn't paid, you may have this creature fight another target creature. (Each deals damage equal to its power to the other.)

Mutant's Prey

Target creature you control with a +1/+1 counter on it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Struggle for Skemfar

Put a +1/+1 counter on target creature you control. Then that creature fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)
Foretell {G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Mortal's Resolve

Target creature gets +1/+1 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Magus of the Order

{G}, {T}, Sacrifice this creature and another green creature: Search your library for a green creature card, put it onto the battlefield, then shuffle.

Allosaurus Shepherd

This spell can't be countered.
Green spells you control can't be countered.
{4}{G}{G}: Until end of turn, each Elf creature you control has base power and toughness 5/5 and becomes a Dinosaur in addition to its other creature types.

Garruk, Primal Hunter

+1: Create a 3/3 green Beast creature token.
−3: Draw cards equal to the greatest power among creatures you control.
−6: Create a 6/6 green Wurm creature token for each land you control.

Arbor Elf

Genesis 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.
This creature enters with X +1/+1 counters on it.

Barrier Breach

Exile up to three target enchantments.
Cycling {2} ({2}, Discard this card: Draw a card.)

Master's Rebuke

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)