Amaranthine Wall

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

Mobile Fort

Defender (This creature can't attack.)
{3}: Mobile Fort gets +3/-1 until end of turn and can attack this turn as though it didn't have defender. Activate only once each turn.

Steel Wall

Necropolis

Defender (This creature can't attack.)
Exile a creature card from your graveyard: Put X +0/+1 counters on Necropolis, where X is the exiled card's mana value.

Angelic Wall

Defender (This creature can't attack.)
Flying

Academy Wall

Defender
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card. This ability triggers only once each turn.

Wall of Spears

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

Glacial Wall

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.)

Hover Barrier

Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Crenellated Wall

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

Wall of Denial

Defender, flying
Shroud (This creature can't be the target of spells or abilities.)

Sol Ring

Arcades, the Strategist

Flying, vigilance
Whenever a creature you control with defender enters, draw a card.
Each creature you control with defender assigns combat damage equal to its toughness rather than its power and can attack as though it didn't have defender.

Have

Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Wall of Faith

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

Weathered Sentinels

Defender, vigilance, reach, trample
Weathered Sentinels can attack players who attacked you during their last turn as though it didn't have defender.
Whenever Weathered Sentinels attacks, it gets +3/+3 and gains indestructible until end of turn.

Fortified Rampart

Jungle Barrier

Defender (This creature can't attack.)
When Jungle Barrier enters, draw a card.

Coral Colony

Defender
{1}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender. (To mill a card, a player puts the top card of their library into their graveyard.)

Secret Door

Defender
{4}{U}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)