Lobber Crew

Defender
{T}: Lobber Crew deals 1 damage to each opponent.
Whenever you cast a multicolored spell, untap Lobber Crew.

Wall of Vapor

Defender (This creature can't attack.)
Prevent all damage that would be dealt to Wall of Vapor by creatures it's blocking.

Tidewater Minion

Defender (This creature can't attack.)
{4}: Tidewater Minion loses defender until end of turn.
{T}: Untap target permanent.

Wall of Corpses

Defender (This creature can't attack.)
{B}, Sacrifice Wall of Corpses: Destroy target creature Wall of Corpses is blocking.

Hired Torturer

Defender
{3}{B}, {T}: Target opponent loses 2 life, then reveals a card at random from their hand.

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 Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, Electrostatic Field deals 1 damage to each opponent.

Stinging Barrier

Defender (This creature can't attack.)
{U}, {T}: Stinging Barrier deals 1 damage to any target.

Vent Sentinel

Defender
{1}{R}, {T}: Vent Sentinel deals damage to target player or planeswalker equal to the number of creatures you control with defender.

Blight Pile

Defender
{2}{B}, {T}: Each opponent loses X life, where X is the number of creatures with defender you control.

Mnemonic Wall

Defender
When Mnemonic Wall enters the battlefield, you may return target instant or sorcery card from your graveyard to your hand.

Wall of Limbs

Defender (This creature can't attack.)
Whenever you gain life, put a +1/+1 counter on Wall of Limbs.
{5}{B}{B}, Sacrifice Wall of Limbs: Target player loses X life, where X is Wall of Limbs's power.

Brimstone Trebuchet

Defender, reach
{T}: Brimstone Trebuchet deals 1 damage to each opponent.
Whenever a Knight enters the battlefield under your control, untap Brimstone Trebuchet.

Wall of Tombstones

Defender (This creature can't attack.)
At the beginning of your upkeep, change Wall of Tombstones's base toughness to 1 plus the number of creature cards in your graveyard. (This effect lasts indefinitely.)

Surge Engine

Defender
{U}: Surge Engine loses defender and gains "This creature can't be blocked."
{2}{U}: Surge Engine becomes blue and has base power and toughness 5/4. Activate only if Surge Engine doesn't have defender.
{4}{U}{U}: Draw three cards. Activate only if Surge Engine is blue and only once.

Manor Gargoyle

Defender
Manor Gargoyle has indestructible as long as it has defender.
{1}: Until end of turn, Manor Gargoyle loses defender and gains flying.

Wall of Souls

Defender (This creature can't attack.)
Whenever Wall of Souls is dealt combat damage, it deals that much damage to target opponent or planeswalker.

Wall of Vipers

Defender (This creature can't attack.)
{3}: Destroy Wall of Vipers and target creature it's blocking. Any player may activate this ability.

Spear Spewer

Defender
{T}: Spear Spewer deals 1 damage to each player.

Wall of Forgotten Pharaohs

Defender
{T}: Wall of Forgotten Pharaohs deals 1 damage to target player or planeswalker. Activate only if you control a Desert or there is a Desert card in your graveyard.

Unruly Catapult

Defender
{T}: Unruly Catapult deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Unruly Catapult.

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Flowstone Wall

Defender (This creature can't attack.)
{R}: Flowstone Wall gets +1/-1 until end of turn.

Wall of Shadows

Defender (This creature can't attack.)
Prevent all damage that would be dealt to Wall of Shadows by creatures it's blocking.
Wall of Shadows can't be the target of spells that can target only Walls or of abilities that can target only Walls.