Balduvian Bears

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.)

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.

Pale Bears

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

Owlbear

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

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.

Ashcoat Bear

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

Bear Cub

Mother Bear

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

Runeclaw Bear

Druid's Familiar

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. 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.

Alpine Grizzly

Surrak and Goreclaw

Trample
Other creatures you control have trample.
Whenever another nontoken creature enters the battlefield under your control, put a +1/+1 counter on it. It gains haste until end of turn.

Snow-Covered Forest

River Bear

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.

Werebear

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

Ulvenwald Bear

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

Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw, Terror of Qal Sisma attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Copper Host Crusher

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

Golden Bear

Dragon-Scarred Bear

Formidable — {1}{G}: Regenerate Dragon-Scarred Bear. Activate only if creatures you control have total power 8 or greater.

Professor of Zoomancy

When Professor of Zoomancy enters the battlefield, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."