Professor of Zoomancy

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

Mother Bear

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

Forest

Masked Vandal

Changeling (This card is every creature type.)
When this creature enters, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Ashcoat Bear

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

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 this creature deals combat damage to a player, you may sacrifice it. When you do, destroy target artifact or enchantment.

Flaxen Intruder // Welcome Home

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.)

Pridemalkin

When this creature enters, put a +1/+1 counter on target creature you control.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Gladewalker Ritualist

Changeling (This card is every creature type.)
Whenever another creature you control named Gladewalker Ritualist enters, draw a card.

Yorvo, Lord of Garenbrig

Yorvo enters with four +1/+1 counters on it.
Whenever another green creature you control enters, put a +1/+1 counter on Yorvo. Then if that creature's power is greater than Yorvo's power, put another +1/+1 counter on Yorvo.

Giant Growth

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

Warbriar Blessing

Enchant creature you control
When this Aura enters, enchanted creature fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)
Enchanted creature gets +0/+2.

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.