Flowstone Giant

{R}: Flowstone Giant gets +2/-2 until end of turn.

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.)

Pharagax Giant

Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Pharagax Giant enters, if tribute wasn't paid, Pharagax Giant deals 5 damage to each opponent.

Squash

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

Giant's Ire

Giant's Ire deals 4 damage to target player or planeswalker. If you control a Giant, draw a card.

Masked Vandal

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

Manor Gate

Manor Gate enters tapped.
As Manor Gate enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Stinkdrinker Daredevil

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

Cinderheart Giant

Trample
When Cinderheart Giant dies, it deals 7 damage to a creature an opponent controls chosen at random.

Forest

Hotheaded Giant

Haste
Hotheaded Giant enters with two -1/-1 counters on it unless you've cast another red spell this turn.

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Hammer Dropper

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Blind-Spot Giant

Blind-Spot Giant can't attack or block unless you control another Giant.

Guardian Gladewalker

Changeling (This card is every creature type.)
When Guardian Gladewalker enters, put a +1/+1 counter on target creature.

Ondu Giant

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

Cave of Temptation

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}, Sacrifice Cave of Temptation: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Elvish Handservant

Whenever a player casts a Giant spell, you may put a +1/+1 counter on Elvish Handservant.

Quirion Elves

As Quirion Elves enters, choose a color.
{T}: Add {G}.
{T}: Add one mana of the chosen color.

Hill Giant Herdgorger

When Hill Giant Herdgorger enters, you gain 3 life.

Crush Underfoot

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

Winding Way

Choose creature or land. Reveal the top four cards of your library. Put all cards of the chosen type revealed this way into your hand and the rest into your graveyard.

Tall as a Beanstalk

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