Rune-Sealed Wall

Defender
{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Felothar the Steadfast

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{3}, {T}, Sacrifice another creature: Draw cards equal to the sacrificed creature's toughness, then discard cards equal to its power.

The Walls of Ba Sing Se

Defender
Other permanents you control have indestructible.

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.

Axebane Guardian

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

Glacial Wall

Shield-Wall Sentinel

Defender
When this creature enters, you may search your library for a creature card with defender, reveal it, put it into your hand, then shuffle.

Stalwart Shield-Bearers

Defender
Other creatures you control with defender get +0/+2.

Sunscape Familiar

Defender (This creature can't attack.)
Green spells and blue spells you cast cost {1} less to cast.

High Alert

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{2}{W}{U}: Untap target creature.

Wall of Denial

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