Naturalize

Circle of the Moon Druid

Bear Form — During your turn, Circle of the Moon Druid is a Bear with base power and toughness 4/2. (It loses all other creature types.)

Alpine Grizzly

Thunderfoot Baloth

Trample
Lieutenant — As long as you control your commander, Thunderfoot Baloth gets +2/+2 and other creatures you control get +2/+2 and have trample.

Wurm's Tooth

Whenever a player casts a green spell, you may gain 1 life.

Game-Trail Changeling

Changeling (This card is every creature type.)
Trample

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

Master Chef

Commander creatures you own have "This creature enters with an additional +1/+1 counter on it" and "Other creatures you control enter with an additional +1/+1 counter on them."

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Blanchwood Armor

Enchant creature
Enchanted creature gets +1/+1 for each Forest you control.

Titanic Growth

Target creature gets +4/+4 until end of turn.

Druid's Familiar

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Druid's Familiar is paired with another creature, each of those creatures gets +2/+2.

Balduvian Bears

Awaken the Bear

Target creature gets +3/+3 and gains trample until end of turn.

Bear Down

Destroy target artifact or enchantment. (Then exile this card. You may cast the creature later from exile.)

Stormkeld Vanguard

Stormkeld Vanguard can't be blocked by creatures with power 2 or less.

Stormkeld Vanguard // Bear Down

Copper Host Crusher

Trample
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Webweaver Changeling

Changeling (This card is every creature type.)
Reach
When Webweaver Changeling enters, if there are three or more creature cards in your graveyard, you gain 5 life.

Instrument of the Bards

At the beginning of your upkeep, you may put a harmony counter on Instrument of the Bards.
{3}{G}, {T}: Search your library for a creature card with mana value equal to the number of harmony counters on Instrument of the Bards, reveal it, and put it into your hand. If that card is legendary, create a Treasure token. Then shuffle.

Muraganda Petroglyphs

Mother Bear

{3}{G}{G}, Exile Mother Bear from your graveyard: Create two 2/2 green Bear creature tokens. Activate only as a sorcery.

Guardian Gladewalker

Changeling (This card is every creature type.)
When Guardian Gladewalker enters, put a +1/+1 counter on target creature.

Runeclaw Bear

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Werebear

{T}: Add {G}.
Threshold — Werebear gets +3/+3 as long as seven or more cards are in your graveyard.

Nissa's Pilgrimage

Search your library for up to two basic Forest cards, reveal those cards, and put one onto the battlefield tapped and the rest into your hand. Then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, search your library for up to three basic Forest cards instead of two.

Broken Bond

Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.

Universal Automaton

Changeling (This card is every creature type.)

Giant Growth

Target creature gets +3/+3 until end of turn.

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Owlbear

Trample
Keen Senses — When Owlbear enters, draw a card.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Foe-Razer Regent

Flying
When Foe-Razer Regent enters, you may have it fight target creature you don't control.
Whenever a creature you control fights, put two +1/+1 counters on it at the beginning of the next end step.

Grizzly Bears

Birthing Boughs

{4}, {T}: Create a 2/2 colorless Shapeshifter creature token with changeling. (It has every creature type.)

Owlbear Shepherd

At the beginning of your end step, if creatures you control have total power 8 or greater, draw a card.

Ayula's Influence

Discard a land card: Create a 2/2 green Bear creature token.

Forest

Striped Bears

Owlbear Cub

Mama's Coming — Whenever Owlbear Cub attacks a player who controls eight or more lands, look at the top eight cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking that player. Put the rest on the bottom of your library in a random order.

Explosive Vegetation

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

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.

Grizzly Fate

Create two 2/2 green Bear creature tokens.
Threshold — Create four 2/2 green Bear creature tokens instead if seven or more cards are in your graveyard.
Flashback {5}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Vivien's Grizzly

{3}{G}: Look at the top card of your library. If it's a creature or planeswalker card, you may reveal it and put it into your hand. If you don't put the card into your hand, put it on the bottom of your library.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Explore

You may play an additional land this turn.
Draw a card.

Gaea's Anthem

Welcome Home

Create three 2/2 green Bear creature tokens. (Then exile this card. You may cast the creature later from exile.)

Flaxen Intruder

Whenever Flaxen Intruder deals combat damage to a player, you may sacrifice it. When you do, destroy target artifact or enchantment.

Flaxen Intruder // Welcome Home

Bear Cub

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Wilson, Refined Grizzly

This spell can't be countered.
Vigilance, reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Choose a Background (You can have a Background as a second commander.)

Llanowar Elves

Ashcoat Bear

Flash (You may cast this spell any time you could cast an instant.)

Hunter's Insight

Choose target creature you control. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

Quirion Beastcaller

Whenever you cast a creature spell, put a +1/+1 counter on Quirion Beastcaller.
When Quirion Beastcaller dies, distribute X +1/+1 counters among any number of target creatures you control, where X is the number of +1/+1 counters on Quirion Beastcaller.

Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Ulvenwald Bear

Morbid — When Ulvenwald Bear enters, if a creature died this turn, put two +1/+1 counters on target creature.

Outmuscle

Put a +1/+1 counter on target creature you control, then it fights target creature you don't control. (Each deals damage equal to its power to the other.)
Adamant — If at least three green mana was spent to cast this spell, the creature you control gains indestructible until end of turn.

Ayula, Queen Among Bears

Whenever another Bear you control enters, choose one —
• Put two +1/+1 counters on target Bear.
• Target Bear you control fights target creature you don't control.

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters with an additional +1/+1 counter on it.

Woodland Changeling

Elvish Mystic

Prizefight

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Animist's Might

This spell costs {2} less to cast if it targets a legendary creature you control.
Target creature you control deals damage equal to twice its power to target creature or planeswalker you don't control.

Gravity Well

Whenever a creature with flying attacks, it loses flying until end of turn.

Titania's Command

Choose two —
• Exile target player's graveyard. You gain 1 life for each card exiled this way.
• Search your library for up to two land cards, put them onto the battlefield tapped, then shuffle.
• Create two 2/2 green Bear creature tokens.
• Put two +1/+1 counters on each creature you control.

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."