Serra's Guardian

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)
Other creatures you control have vigilance.

Greenbelt Guardian

{G}: Target creature gains trample until end of turn.
Exhaust — {3}{G}: Put three +1/+1 counters on this creature. (Activate each exhaust ability only once.)

Lulu, Stern Guardian

Whenever an opponent attacks you, choose target creature attacking you. Put a stun counter on that creature.
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Grim Guardian

Constellation — Whenever this creature or another enchantment you control enters, each opponent loses 1 life.

Auron, Venerated Guardian

Vigilance
Shooting Star — Whenever Auron attacks, put a +1/+1 counter on it. When you do, exile target creature defending player controls with power less than Auron's power until Auron leaves the battlefield.

Guardians of Meletis

Guardian of the Gateless

Flying
This creature can block any number of creatures.
Whenever this creature blocks, it gets +1/+1 until end of turn for each creature it's blocking.

Soulbound Guardians

Guardian of the Guildpact

Banishing Coils

Exile target artifact or enchantment. (Then exile this card. You may cast the creature later from exile.)

Guardian Naga

Vigilance
During your turn, prevent all damage that would be dealt to this creature.

Guardian Naga // Banishing Coils

Haunted Guardian

Avacyn, Guardian Angel

Flying, vigilance
{1}{W}: Prevent all damage that would be dealt to another target creature this turn by sources of the color of your choice.
{5}{W}{W}: Prevent all damage that would be dealt to target player or planeswalker this turn by sources of the color of your choice.

Bronze Guardian

Double strike
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Other artifacts you control have ward {2}.
Bronze Guardian's power is equal to the number of artifacts you control.

Armored Guardian

{1}{W}{W}: Target creature you control gains protection from the color of your choice until end of turn.
{1}{U}{U}: This creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Kimahri, Valiant Guardian

Vigilance
Ronso Rage — At the beginning of combat on your turn, put a +1/+1 counter on Kimahri and tap target creature an opponent controls. Then you may have Kimahri become a copy of that creature, except its name is Kimahri, Valiant Guardian and it has vigilance and this ability.

Guardian Augmenter

Flash
Commander creatures you control get +2/+2.
Commanders you control have hexproof.

Ageless Guardian

Angelic Guardian

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever one or more creatures you control attack, they gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Hundred-Handed One

Vigilance
{3}{W}{W}{W}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
As long as this creature is monstrous, it has reach and can block an additional ninety-nine creatures each combat.

Karakyk Guardian

Flying, vigilance, trample
This creature has hexproof if it hasn't dealt damage yet. (It can't be the target of spells or abilities your opponents control.)

Pride Guardian

Defender
Whenever this creature blocks, you gain 3 life.

Guardian of the Ages

Defender (This creature can't attack.)
When a creature attacks you or a planeswalker you control, if this creature has defender, it loses defender and gains trample.

Guardian Lions

Vigilance (Attacking doesn't cause this creature to tap.)

Nemata, Grove Guardian

{2}{G}: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Saproling creatures get +1/+1 until end of turn.

Guardian of New Benalia

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
Whenever this creature enlists a creature, scry 2.
Discard a card: This creature gains indestructible until end of turn. Tap it.

Gold-Forge Garrison

(Transforms from Golden Guardian.)
{T}: Add two mana of any one color.
{4}, {T}: Create a 4/4 colorless Golem artifact creature token.

Golden Guardian

Defender
{2}: This creature fights another target creature you control. When this creature dies this turn, return it to the battlefield transformed under your control.

Golden Guardian // Gold-Forge Garrison

Guardian Kirin

Flying
Whenever another creature you control dies, put a +1/+1 counter on this creature.

Ritual Guardian

Coven — At the beginning of combat on your turn, if you control three or more creatures with different powers, this creature gains lifelink until end of turn.

Axebane Guardian

Defender
{T}: Add X mana in any combination of colors, where X is the number of creatures you control with defender.

Guardians of Akrasa

Defender (This creature can't attack.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Guardian Seraph

Flying
If a source an opponent controls would deal damage to you, prevent 1 of that damage.

Guardians of Oboro

Defender
Modified creatures you control can attack as though they didn't have defender. (Equipment, Auras you control, and counters are modifications.)