Colossus of Akros

Defender, indestructible
{10}: Monstrosity 10. (If this creature isn't monstrous, put ten +1/+1 counters on it and it becomes monstrous.)
As long as Colossus of Akros is monstrous, it has trample and can attack as though it didn't have defender.

Guardians of Meletis

Consulate Skygate

Defender
Reach (This creature can block creatures with flying.)

Hover Barrier

Living Wall

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

Junktroller

Defender
{T}: Put target card from a graveyard on the bottom of its owner's library.

Doorkeeper

Defender
{2}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender.

Steel Wall

Errant, Street Artist

Flash
Defender, haste
{1}{U}, {T}: Copy target spell you control that wasn't cast. You may choose new targets for the copy.

Phenax, God of Deception

Indestructible
As long as your devotion to blue and black is less than seven, Phenax isn't a creature.
Creatures you control have "{T}: Target player mills X cards, where X is this creature's toughness."

Ludevic's Abomination

Ludevic's Test Subject

Defender
{1}{U}: Put a hatchling counter on Ludevic's Test Subject. Then if there are five or more hatchling counters on it, remove all of them and transform it.

Ludevic's Test Subject // Ludevic's Abomination

Blight Pile

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

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.