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

Summoner's Pact

Search your library for a green creature card, reveal it, put it into your hand, then shuffle.
At the beginning of your next upkeep, pay {2}{G}{G}. If you don't, you lose the game.

Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath, Locus of Mana gets +1/+1 for each unspent green mana you have.

Forest

Shared Summons

Search your library for up to two creature cards with different names, reveal them, put them into your hand, then shuffle.

Brutalizer Exarch

When Brutalizer Exarch enters the battlefield, choose one —
• Search your library for a creature card, reveal it, then shuffle and put that card on top.
• Put target noncreature permanent on the bottom of its owner's library.

Cultivator Colossus

Trample
Cultivator Colossus's power and toughness are each equal to the number of lands you control.
When Cultivator Colossus enters the battlefield, you may put a land card from your hand onto the battlefield tapped. If you do, draw a card and repeat this process.