Metallic Mimic

As Metallic Mimic enters the battlefield, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters the battlefield with an additional +1/+1 counter on it.

Bear Cub

Ashcoat Bear

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

Forest Bear

Razorclaw Bear

Whenever Razorclaw Bear becomes blocked, it gets +2/+2 until end of turn.

Rhonas's Monument

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.

Striped Bears

When Striped Bears enters the battlefield, draw a card.

Kudo, King Among Bears

Other creatures have base power and toughness 2/2 and are Bears in addition to their other types.

Runeclaw Bear

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.)

Proteus Machine

Morph {0} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Proteus Machine is turned face up, it becomes the creature type of your choice. (This effect lasts indefinitely.)

Balduvian Bears

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Kindred Boon

As Kindred Boon enters the battlefield, choose a creature type.
{1}{W}: Put a divinity counter on target creature you control of the chosen type.
Each creature you control with a divinity counter on it has indestructible.

River Bear

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Arbor Elf

Golden Bear

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Spectral Bears

Whenever Spectral Bears attacks, if defending player controls no black nontoken permanents, it doesn't untap during your next untap step.

Wild Growth

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

Words of Wilding

{1}: The next time you would draw a card this turn, create a 2/2 green Bear creature token instead.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Ayula's Influence

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

Flowering of the White Tree

Legendary creatures you control get +2/+1 and have ward {1}.
Nonlegendary creatures you control get +1/+1.

Pale Bears

Bearscape

{1}{G}, Exile two cards from your graveyard: Create a 2/2 green Bear creature token.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Grizzly Bears

Ayula, Queen Among Bears

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

Utopia Sprawl

Enchant Forest
As Utopia Sprawl enters the battlefield, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.