Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Forest

Aeronaut Tinkerer

Aeronaut Tinkerer has flying as long as you control an artifact. (It can't be blocked except by creatures with flying or reach.)

Island

Esperzoa

Flying
At the beginning of your upkeep, return an artifact you control to its owner's hand.

Welkin Tern

Flying (This creature can't be blocked except by creatures with flying or reach.)
Welkin Tern can block only creatures with flying.

Inspiration

Darkslick Drake

Flying
When Darkslick Drake dies, draw a card.

Wildsize

Target creature gets +2/+2 and gains trample until end of turn.
Draw a card.

Sky-Eel School

Flying
When Sky-Eel School enters, draw a card, then discard a card.

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Prevent all combat damage that would be dealt this turn.

Countermand

Counter target spell. Its controller mills four cards.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Nissa's Pilgrimage

Search your library for up to two basic Forest cards, reveal those cards, and put one onto the battlefield tapped and the rest into your hand. Then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, search your library for up to three basic Forest cards instead of two.

Kapsho Kitefins

Flying
Whenever Kapsho Kitefins or another creature you control enters, tap target creature an opponent controls.

Timberland Guide

When Timberland Guide enters, put a +1/+1 counter on target creature.

Frost Lynx

When Frost Lynx enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Strider Harness

Equipped creature gets +1/+1 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Primal Huntbeast

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