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.

Bramble Sovereign

Whenever another nontoken creature enters the battlefield, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.

Hamletback Goliath

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

Soul Foundry

Imprint — When Soul Foundry enters the battlefield, you may exile a creature card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.

Arbor Colossus

Reach
{3}{G}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Arbor Colossus becomes monstrous, destroy target creature with flying an opponent controls.

Skarrgan Skybreaker

Bloodthirst 3 (If an opponent was dealt damage this turn, this creature enters the battlefield with three +1/+1 counters on it.)
{1}, Sacrifice Skarrgan Skybreaker: It deals damage equal to its power to any target.

Sunrise Sovereign

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

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

Giant Harbinger

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

Dollhouse of Horrors

{1}, {T}, Exile a creature card from your graveyard: Create a token that's a copy of the exiled card, except it's a 0/0 Construct artifact in addition to its other types and it has "This creature gets +1/+1 for each Construct you control." It gains haste until end of turn. Activate only as a sorcery.

Blind-Spot Giant

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

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Garenbrig Paladin

Adamant — If at least three green mana was spent to cast this spell, Garenbrig Paladin enters the battlefield with a +1/+1 counter on it.
Garenbrig Paladin can't be blocked by creatures with power 2 or less.

Magma Giant

When Magma Giant enters the battlefield, it deals 2 damage to each creature and each player.

Borderland Behemoth

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

Towering Titan

Towering Titan enters the battlefield with X +1/+1 counters on it, where X is the total toughness of other creatures you control.
Sacrifice a creature with defender: All creatures gain trample until end of turn.

Cunning Giant

If Cunning Giant is unblocked, you may have it assign its combat damage to a creature defending player controls.

Adaptive Automaton

As Adaptive Automaton enters the battlefield, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Bloodshot Cyclops

{T}, Sacrifice a creature: Bloodshot Cyclops deals damage equal to the sacrificed creature's power to any target.

Raised by Giants

Commander creatures you own have base power and toughness 10/10 and are Giants in addition to their other types.

Basalt Ravager

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

Furystoke Giant

When Furystoke Giant enters the battlefield, other creatures you control gain "{T}: This creature deals 2 damage to any target" until end of turn.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Bloodfire Colossus

{R}, Sacrifice Bloodfire Colossus: It deals 6 damage to each creature and each player.

Siegebreaker Giant

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
{3}{R}: Target creature can't block this turn.

Rampart Smasher

Rampart Smasher can't be blocked by Knights or Walls.

Hammerfist Giant

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

Thundercloud Shaman

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

Hammerheim Deadeye

Echo {5}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Hammerheim Deadeye enters the battlefield, destroy target creature with flying.

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}

Ondu Giant

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

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.

Firbolg Flutist

Enthralling Performance — When Firbolg Flutist enters the battlefield, gain control of target creature you don't control until end of turn. Untap it. It gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Chancellor of the Forge

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, create a 1/1 red Phyrexian Goblin creature token with haste.
When Chancellor of the Forge enters the battlefield, create X 1/1 red Phyrexian Goblin creature tokens with haste, where X is the number of creatures you control.

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.

Stoneshock Giant

{6}{R}{R}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Stoneshock Giant becomes monstrous, creatures without flying your opponents control can't block this turn.

Earthshaker Giant

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

Boldwyr Intimidator

Cowards can't block Warriors.
{R}: Target creature becomes a Coward until end of turn.
{2}{R}: Target creature becomes a Warrior until end of turn.

God-Pharaoh's Gift

At the beginning of combat on your turn, you may exile a creature card from your graveyard. If you do, create a token that's a copy of that card, except it's a 4/4 black Zombie. It gains haste until end of turn.

Baeloth Barrityl, Entertainer

Creatures your opponents control with power less than Baeloth Barrityl's power are goaded. (They attack each combat if able and attack a player other than you if able.)
Whenever a goaded attacking or blocking creature dies, you create a Treasure token.
Choose a Background (You can have a Background as a second commander.)

Hearthcage Giant

When Hearthcage Giant enters the battlefield, create two 3/1 red Elemental Shaman creature tokens.
Sacrifice an Elemental: Target Giant creature gets +3/+1 until end of turn.