Have

Binding Mummy

Whenever another Zombie you control enters, you may tap target artifact or creature.

Kor Skyfisher

Flying
When Kor Skyfisher enters, return a permanent you control to its owner's hand.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Defiler of Faith

Vigilance
As an additional cost to cast white permanent spells, you may pay 2 life. Those spells cost {W} less to cast if you paid life this way. This effect reduces only the amount of white mana you pay.
Whenever you cast a white permanent spell, create a 1/1 white Soldier creature token.

Stonecloaker

Flash
Flying
When Stonecloaker enters, return a creature you control to its owner's hand.
When Stonecloaker enters, exile target card from a graveyard.

Dust Elemental

Flash (You may cast this spell any time you could cast an instant.)
Flying; fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Dust Elemental enters, return three creatures you control to their owner's hand.

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Spirited Companion

When Spirited Companion enters, draw a card.

Scapegoat

As an additional cost to cast this spell, sacrifice a creature.
Return any number of target creatures you control to their owner's hand.

Cartographer's Hawk

Flying
When Cartographer's Hawk deals combat damage to a player who controls more lands than you, return it to its owner's hand. If you do, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Loyal Gryff

Flash
Flying
When Loyal Gryff enters, you may return another creature you control to its owner's hand.

Rescuer Chwinga

Flash
Natural Shelter — When Rescuer Chwinga enters, you may return another permanent you control to its owner's hand.

Symmetry Matrix

Whenever a creature you control with power equal to its toughness enters, you may pay {1}. If you do, draw a card.

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Inspiring Overseer

Flying
When Inspiring Overseer enters, you gain 1 life and draw a card.

Loyal Warhound

Vigilance
When Loyal Warhound enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Aviary Mechanic

When Aviary Mechanic enters, you may return another permanent you control to its owner's hand.

Whitemane Lion

Flash
When Whitemane Lion enters, return a creature you control to its owner's hand.

Bond of Discipline

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.