Illuna, Apex of Wishes
Legendary Creature — Beast Elemental Dinosaur
Mutate 
(If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying, trample
Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand.
Justine Mara Andersen
Rulings
Illuna's last ability exiles the cards face up. All players will see what the card is if you put it into your hand.
(wotc • 2020-04-17)
Any land, instant, and sorcery cards exiled this way remain in exile.
(wotc • 2020-04-17)
If an Aura is put onto the battlefield without being cast, the Aura's controller-to-be chooses what it will enchant as it enters the battlefield. An Aura put onto the battlefield this way doesn't target anything (so it could be attached to an opponent's permanent with hexproof, for example), but the Aura's enchant ability restricts what it can be attached to. If the Aura can't legally be attached to anything, it remains in its current zone.
(wotc • 2020-04-17)
A nonland permanent card is an artifact, creature, enchantment, or planeswalker card.
(wotc • 2020-04-17)
You choose whether to put the card into your hand or onto the battlefield after seeing what the card is.
(wotc • 2020-04-17)
Rulings
Illuna's last ability exiles the cards face up. All players will see what the card is if you put it into your hand.
(wotc • 2020-04-17)
Any land, instant, and sorcery cards exiled this way remain in exile.
(wotc • 2020-04-17)
If an Aura is put onto the battlefield without being cast, the Aura's controller-to-be chooses what it will enchant as it enters the battlefield. An Aura put onto the battlefield this way doesn't target anything (so it could be attached to an opponent's permanent with hexproof, for example), but the Aura's enchant ability restricts what it can be attached to. If the Aura can't legally be attached to anything, it remains in its current zone.
(wotc • 2020-04-17)
A nonland permanent card is an artifact, creature, enchantment, or planeswalker card.
(wotc • 2020-04-17)
You choose whether to put the card into your hand or onto the battlefield after seeing what the card is.
(wotc • 2020-04-17)