Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Scab-Clan Giant

When Scab-Clan Giant enters, it fights target creature an opponent controls chosen at random.

Tall as a Beanstalk

Enchant creature
Enchanted creature gets +3/+3, has reach, and is a Giant in addition to its other types.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Oathsworn Giant

Vigilance
Other creatures you control get +0/+2 and have vigilance.

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Kalemne, Disciple of Iroas

Double strike, vigilance
Whenever you cast a creature spell with mana value 5 or greater, you get an experience counter.
Kalemne, Disciple of Iroas gets +1/+1 for each experience counter you have.

Itlimoc, Cradle of the Sun

(Transforms from Growing Rites of Itlimoc.)
{T}: Add {G}.
{T}: Add {G} for each creature you control.

Growing Rites of Itlimoc

When Growing Rites of Itlimoc enters, look at the top four cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
At the beginning of your end step, if you control four or more creatures, transform Growing Rites of Itlimoc.

Growing Rites of Itlimoc // Itlimoc, Cradle of the Sun

Brion Stoutarm

Lifelink
{R}, {T}, Sacrifice another creature: Brion Stoutarm deals damage equal to the sacrificed creature's power to target player or planeswalker.

Ancient Amphitheater

As Ancient Amphitheater enters, you may reveal a Giant card from your hand. If you don't, Ancient Amphitheater enters tapped.
{T}: Add {R} or {W}.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Cast Off

Destroy all non-Giant creatures. (Then exile this card. You may cast the creature later from exile.)

Realm-Cloaked Giant

Realm-Cloaked Giant // Cast Off

Rosheen Meanderer

{T}: Add {C}{C}{C}{C}. Spend this mana only on costs that contain {X}.

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.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Concerted Effort

At the beginning of each upkeep, creatures you control gain flying until end of turn if a creature you control has flying. The same is true for fear, first strike, double strike, landwalk, protection, trample, and vigilance.

Sol Ring

Minsc, Beloved Ranger

When Minsc, Beloved Ranger enters, create Boo, a legendary 1/1 red Hamster creature token with trample and haste.
{X}: Until end of turn, target creature you control has base power and toughness X/X and becomes a Giant in addition to its other types. Activate only as a sorcery.

Quakebringer

Your opponents can't gain life.
At the beginning of your upkeep, Quakebringer deals 2 damage to each opponent. This ability triggers only if Quakebringer is on the battlefield or if Quakebringer is in your graveyard and you control a Giant.
Foretell {2}{R}{R}

Fire Giant's Fury

Target Giant you control gets +2/+2 and gains trample until end of turn. Whenever it deals combat damage to a player this turn, exile that many cards from the top of your library. Until the end of your next turn, you may play those cards.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Ascend from Avernus

Return all creature and planeswalker cards with mana value X or less from your graveyard to the battlefield. Exile Ascend from Avernus.

Grasping Giant

Vigilance
Whenever Grasping Giant becomes blocked by a creature, exile that creature until Grasping Giant leaves the battlefield.

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Mountain

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Hamletback Goliath

Whenever another creature enters, you may put X +1/+1 counters on Hamletback Goliath, where X is that creature's power.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Crystalline Giant

At the beginning of combat on your turn, choose a kind of counter at random that Crystalline Giant doesn't have on it from among flying, first strike, deathtouch, hexproof, lifelink, menace, reach, trample, vigilance, and +1/+1. Put a counter of that kind on Crystalline Giant.

Tectonic Giant

Whenever Tectonic Giant attacks or becomes the target of a spell an opponent controls, choose one —
• Tectonic Giant deals 3 damage to each opponent.
• Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.

Icon of Ancestry

As Icon of Ancestry enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Zalto, Fire Giant Duke

Trample
Whenever Zalto, Fire Giant Duke is dealt damage, venture into the dungeon. (Enter the first room or advance to the next room.)

Palisade Giant

All damage that would be dealt to you and other permanents you control is dealt to Palisade Giant instead.

Awaken the Ancient

Enchant Mountain
Enchanted Mountain is a 7/7 red Giant creature with haste. It's still a land.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Two-Headed Giant

Whenever Two-Headed Giant attacks, flip two coins. If both coins come up heads, Two-Headed Giant gains double strike until end of turn. If both coins come up tails, Two-Headed Giant gains menace until end of turn.

Basalt Ravager

When Basalt Ravager enters, it deals X damage to any target, where X is the greatest number of creatures you control that have a creature type in common.

Crush Underfoot

Choose a Giant creature you control. It deals damage equal to its power to target creature.

Thundercloud Shaman

When Thundercloud Shaman enters, it deals damage equal to the number of Giants you control to each non-Giant creature.

Stinkdrinker Daredevil

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

Shatterskull Charger

Kicker {2}
Trample, haste
If Shatterskull Charger was kicked, it enters with a +1/+1 counter on it.
At the beginning of your end step, if Shatterskull Charger doesn't have a +1/+1 counter on it, return it to its owner's hand.

Earthshaker Giant

Trample
When Earthshaker Giant enters, other creatures you control get +3/+3 and gain trample until end of turn.

Giant Harbinger

When Giant Harbinger enters, you may search your library for a Giant card, reveal it, then shuffle and put that card on top.

Plains

Skybeast Tracker

Reach
Whenever you cast a spell with mana value 5 or greater, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Squash

This spell costs {3} less to cast if you control a Giant.
Squash deals 6 damage to target creature or planeswalker.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

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.

Kodama's Reach

Utopia Sprawl

Enchant Forest
As Utopia Sprawl enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

Swathcutter Giant

Vigilance
Whenever Swathcutter Giant attacks, it deals 1 damage to each creature defending player controls.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Giant Inheritance

Enchant creature
Enchanted creature gets +5/+5 and has "Whenever this creature attacks, create a Monster Role token attached to up to one target attacking creature." (Enchanted creature gets +1/+1 and has trample.)
When Giant Inheritance is put into a graveyard from the battlefield, return it to its owner's hand.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ondu Giant

When Ondu Giant enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sunrise Sovereign

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Hammerfist Giant

{T}: Hammerfist Giant deals 4 damage to each creature without flying and each player.

Forest

Assemble the Entmoot

Creatures you control have reach.
Sacrifice Assemble the Entmoot: Create three tapped X/X green Treefolk creature tokens, where X is the amount of life you gained this turn. Put a reach counter on each of them.

Overgrowth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}{G}.

Lairwatch Giant

Lairwatch Giant can block an additional creature each combat.
Whenever Lairwatch Giant blocks two or more creatures, it gains first strike until end of turn.

Borderland Behemoth

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

Surtland Flinger

Whenever Surtland Flinger attacks, you may sacrifice another creature. When you do, Surtland Flinger deals damage equal to the sacrificed creature's power to any target. If the sacrificed creature was a Giant, Surtland Flinger deals twice that much damage instead.

Jareth, Leonine Titan

Whenever Jareth, Leonine Titan blocks, it gets +7/+7 until end of turn.
{W}: Jareth gains protection from the color of your choice until end of turn.