Zoological Study

Mill five cards, then return a creature card milled this way to your hand. (Then exile this card. You may cast the artifact later from exile.)

Monster Manual

{1}{G}, {T}: You may put a creature card from your hand onto the battlefield.

Monster Manual // Zoological Study

Aether Vial

At the beginning of your upkeep, you may put a charge counter on this artifact.
{T}: You may put a creature card with mana value equal to the number of charge counters on this artifact from your hand onto the battlefield.

Oviya, Automech Artisan

Each creature that's attacking one of your opponents has trample.
{G}, {T}: You may put a creature or Vehicle card from your hand onto the battlefield. If you put an artifact onto the battlefield this way, put two +1/+1 counters on it.

Next of Kin

Enchant creature
When enchanted creature dies, you may put a creature card you own with lesser mana value from your hand or from the command zone onto the battlefield. If you do, return this card to the battlefield attached to that creature at the beginning of the next end step.

Hunting Grounds

Threshold — As long as there are seven or more cards in your graveyard, this enchantment has "Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield."

Sledge-Class Seedship

Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 7+.)
7+ | Flying
Whenever this Spacecraft attacks, you may put a creature card from your hand onto the battlefield.

Elvish Piper

{G}, {T}: You may put a creature card from your hand onto the battlefield.

Kinscaer Sentry

First strike, lifelink
Whenever this creature attacks, you may put a creature card with mana value X or less from your hand onto the battlefield tapped and attacking, where X is the number of attacking creatures you control.

Norwood Priestess

{T}: You may put a green creature card from your hand onto the battlefield. Activate only during your turn, before attackers are declared.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Wildsong Howler

Whenever this creature enters or transforms into Wildsong Howler, look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Howlpack Piper

This spell can't be countered.
{1}{G}, {T}: You may put a creature card from your hand onto the battlefield. If it's a Wolf or Werewolf, untap this creature. Activate only as a sorcery.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Howlpack Piper // Wildsong Howler

Champion of Rhonas

You may exert this creature as it attacks. When you do, you may put a creature card from your hand onto the battlefield. (An exerted creature won't untap during your next untap step.)

Meek Attack

{1}{R}: You may put a creature card with total power and toughness 5 or less from your hand onto the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice that creature.

Rienne, Angel of Rebirth

Flying
Other multicolored creatures you control get +1/+0.
Whenever another multicolored creature you control dies, return it to its owner's hand at the beginning of the next end step.