Wall of Junk

Defender (This creature can't attack.)
When Wall of Junk blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Wall of Omens

Defender
When Wall of Omens enters the battlefield, draw a card.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Wall of One Thousand Cuts

Defender, flying
{W}: Wall of One Thousand Cuts can attack this turn as though it didn't have defender.

Bill the Pony

When Bill the Pony enters the battlefield, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Sacrifice a Food: Until end of turn, target creature you control assigns combat damage equal to its toughness rather than its power.

Amaranthine Wall

Defender
{2}: Amaranthine Wall gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Wall of Spears

Defender (This creature can't attack.)
First strike

Crush Contraband

Choose one or both —
• Exile target artifact.
• Exile target enchantment.

Wall of Resistance

Defender (This creature can't attack.)
Flying
At the beginning of each end step, if Wall of Resistance was dealt damage this turn, put a +0/+1 counter on it.

Alabaster Wall

Defender (This creature can't attack.)
{T}: Prevent the next 1 damage that would be dealt to any target this turn.

Steel Wall

Shield-Wall Sentinel

Defender
When Shield-Wall Sentinel enters the battlefield, you may search your library for a creature card with defender, reveal it, put it into your hand, then shuffle.

Wall of Faith

Defender (This creature can't attack.)
{W}: Wall of Faith gets +0/+1 until end of turn.

Plains

Angelic Wall

Defender (This creature can't attack.)
Flying

Wall of Essence

Defender (This creature can't attack.)
Whenever Wall of Essence is dealt combat damage, you gain that much life.

Crenellated Wall

Defender (This creature can't attack.)
{T}: Target creature gets +0/+4 until end of turn.

Shield Wall

Creatures you control get +0/+2 until end of turn.

Wall of Hope

Defender (This creature can't attack.)
Whenever Wall of Hope is dealt damage, you gain that much life.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Indestructibility

Enchant permanent
Enchanted permanent has indestructible. (Effects that say "destroy" don't destroy that permanent. A creature with indestructible can't be destroyed by damage.)

Wall of Swords

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Wall of Glare

Defender (This creature can't attack.)
Wall of Glare can block any number of creatures.