Elvish Handservant

Whenever a player casts a Giant spell, you may put a +1/+1 counter on Elvish Handservant.

Circle of the Moon Druid

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

Howling Giant

Reach (This creature can block creatures with flying.)
When Howling Giant enters the battlefield, create two 2/2 green Wolf creature tokens.

Ayula's Influence

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

Decorated Champion

Whenever another Warrior enters the battlefield under your team's control, put a +1/+1 counter on Decorated Champion.

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.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Crash the Party

Create a tapped 4/4 green Rhino Warrior creature token for each tapped creature you control.

Werebear

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

Owlbear

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

Hill Giant Herdgorger

When Hill Giant Herdgorger enters the battlefield, you gain 3 life.

Forest

Raised by Giants

Commander creatures you own have base power and toughness 10/10 and are Giants in addition to their other types.

Bearscape

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

Fertile Footsteps

Search your library for a basic land card, put it onto the battlefield, then shuffle. (Then exile this card. You may cast the creature later from exile.)

Beanstalk Giant

Beanstalk Giant's power and toughness are each equal to the number of lands you control.

Beanstalk Giant // Fertile Footsteps

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

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.)