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.

Surrak and Goreclaw

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

Ulvenwald Bear

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

Duskana, the Rage Mother

When Duskana, the Rage Mother enters, draw a card for each creature you control with base power and toughness 2/2.
Whenever a creature you control with base power and toughness 2/2 attacks, it gets +3/+3 until end of turn.

Baird, Argivian Recruiter

At the beginning of your end step, if you control a creature with power greater than its base power, create a 1/1 white Soldier creature token.

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.)

Bear Cub

Kudo, King Among Bears

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

Striped Bears

Ashcoat Bear

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

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.

Copper Host Crusher

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

Pale Bears

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

Rampaging Yao Guai

Vigilance, trample
Rampaging Yao Guai enters with X +1/+1 counters on it.
When Rampaging Yao Guai enters, destroy any number of target artifacts and/or enchantments with total mana value X or less.

River Bear

Razorclaw Bear

Whenever Razorclaw Bear becomes blocked, it gets +2/+2 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.

Plains

Ruxa, Patient Professor

Whenever Ruxa, Patient Professor enters or attacks, return target creature card with no abilities from your graveyard to your hand.
Creatures you control with no abilities get +1/+1.
For each creature you control with no abilities, you may have that creature assign its combat damage as though it weren't blocked.

Forest

Professor of Zoomancy

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

Guardian of New Benalia

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
Whenever Guardian of New Benalia enlists a creature, scry 2.
Discard a card: Guardian of New Benalia gains indestructible until end of turn. Tap it.

Mountain

Mother Bear

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

Alpine Grizzly

Owlbear

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

Inti, Seneschal of the Sun

Whenever you attack, you may discard a card. When you do, put a +1/+1 counter on target attacking creature. It gains trample until end of turn.
Whenever you discard one or more cards, exile the top card of your library. You may play that card until your next end step.

Exuberant Wolfbear

Whenever Exuberant Wolfbear attacks, you may change the base power and toughness of target Human you control to Exuberant Wolfbear's power and toughness 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.

Guardian Augmenter

Flash
Commander creatures you control get +2/+2.
Commanders you control have hexproof.

Balduvian Bears

Spectral Bears

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

Runeclaw Bear

Three Visits

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

Forest Bear

Fetch Quest

Mill seven cards. Then put a creature, enchantment, or land card from among the milled cards onto the battlefield.

Bramble Familiar

{T}: Add {G}.
{1}{G}, {T}, Discard a card: Return Bramble Familiar to its owner's hand.

Bramble Familiar // Fetch Quest

Rampant Growth

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

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.

Arcee, Acrobatic Coupe

Living metal (During your turn, this Vehicle is also a creature.)
Whenever you cast a spell that targets one or more creatures or Vehicles you control, put that many +1/+1 counters on Arcee. Convert Arcee.

Arcee, Sharpshooter

More Than Meets the Eye {R}{W} (You may cast this card converted for {R}{W}.)
First strike
{1}, Remove one or more +1/+1 counters from Arcee: It deals that much damage to target creature. Convert Arcee.