Wall of Tears

Defender (This creature can't attack.)
Whenever Wall of Tears blocks a creature, return that creature to its owner's hand at end of combat.

Wall of Brambles

Defender (This creature can't attack.)
{G}: Regenerate Wall of Brambles.

Swamp Mosquito

Flying
Whenever Swamp Mosquito attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Siren's Call

Cast this spell only during an opponent's turn, before attackers are declared.
Creatures the active player controls attack this turn if able.
At the beginning of the next end step, destroy all non-Wall creatures that player controls that didn't attack this turn. Ignore this effect for each creature the player didn't control continuously since the beginning of the turn.

Thunder Wall

Defender (This creature can't attack.)
Flying
{U}: Thunder Wall gets +1/+1 until end of turn.

Glyph of Doom

Choose target Wall creature. At this turn's next end of combat, destroy all creatures that were blocked by that creature this turn.

Living Wall

Defender (This creature can't attack.)
{1}: Regenerate Living Wall.

Wall of Wonder

Defender (This creature can't attack.)
{2}{U}{U}: Wall of Wonder gets +4/-4 until end of turn and can attack this turn as though it didn't have defender.

Wall of Spears

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

Shifting Wall

Defender (This creature can't attack.)
Shifting Wall enters with X +1/+1 counters on it.

Sabertooth Cobra

Whenever Sabertooth Cobra deals damage to a player, that player gets a poison counter. The player gets another poison counter at the beginning of their next upkeep unless they pay {2} before that step. (A player with ten or more poison counters loses the game.)

Walking Wall

Defender
{3}: Walking Wall gets +3/-1 until end of turn and can attack this turn as though it didn't have defender. Activate only once each turn.

Serpent Generator

{4}, {T}: Create a 1/1 colorless Snake artifact creature token. It has "Whenever this creature deals damage to a player, that player gets a poison counter." (A player with ten or more poison counters loses the game.)

Crypt Cobra

Whenever Crypt Cobra attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Dark Maze

Defender (This creature can't attack.)
{0}: Dark Maze can attack this turn as though it didn't have defender. Exile it at the beginning of the next end step.

Wall of Shields

Defender (This creature can't attack.)
Banding (If any creatures with banding you control are blocking a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by.)

The Hive

{5}, {T}: Create a 1/1 colorless Insect artifact creature token with flying named Wasp. (It can't be blocked except by creatures with flying or reach.)

Wall of Wood

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.

Suq'Ata Assassin

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Suq'Ata Assassin attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Glacial Wall

Glyph of Delusion

Put X glyph counters on target creature that target Wall blocked this turn, where X is the power of that blocked creature. The creature gains "This creature doesn't untap during your untap step if it has a glyph counter on it" and "At the beginning of your upkeep, remove a glyph counter from this creature."