Etali's Favor (149) [The Lost Caverns of Ixalan]

Enchant creature you control When this Aura enters, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.) Enchanted creature gets +1/+1 and has trample.