Bearer of the Heavens

When Bearer of the Heavens dies, destroy all permanents at the beginning of the next end step.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Borderland Behemoth

Trample
Borderland Behemoth gets +4/+4 for each other Giant you control.

Forest

Mountain

Sunrise Sovereign

Other Giant creatures you control get +2/+2 and have trample.

Giantbaiting

Create a 4/4 red and green Giant Warrior creature token with haste. Exile it at the beginning of the next end step.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it.)

Stinkdrinker Daredevil

Giant spells you cast cost {2} less to cast.

Calamity Bearer

If a Giant source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Hill Giant Herdgorger

When Hill Giant Herdgorger enters, you gain 3 life.

Yorvo, Lord of Garenbrig

Yorvo, Lord of Garenbrig 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.

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.