Whenever a creature enters the battlefield under your control, you may look at the top X cards of your library, where X is that creature's power. If you do, put one of those cards on top of your library and the rest on the bottom of your library in any order.

Enchant creature
: Put a +1/+1 counter on enchanted creature.

As Declaration of Naught enters the battlefield, choose a card name.
: Counter target spell with the chosen name.

Choose target artifact or enchantment. Its owner shuffles it into their library.

Flash
Flying
When Dewdrop Spy enters the battlefield, look at the top card of target player's library.

Return target nonland permanent to its owner's hand.

Choose a creature type. Draw a card for each permanent you control of that type.

Equipped creature has "Whenever you draw a card, this creature gets +1/+1 and gains flying until end of turn" and ": Draw a card."
Whenever a Wizard creature enters the battlefield, you may attach Diviner's Wand to it.
Equip

As Door of Destinies enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Target creature gets +3/+3 until end of turn.
Reinforce 1— (, Discard this card: Put a +1/+1 counter on target creature.)

Prowl (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Goblin or Rogue.)
When Earwig Squad enters the battlefield, if its prowl cost was paid, search target opponent's library for three cards and exile them. Then that player shuffles their library.

, Exile a Treefolk card from your graveyard: Search your library for up to two Forest cards and put them onto the battlefield tapped. Then shuffle your library.

Flying
: Put Fencer Clique on top of its owner's library.

: Up to two target Swamps each become 3/5 Treefolk Warrior creatures in addition to their other types until end of turn.

Fertilid enters the battlefield with two +1/+1 counters on it.
, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles their library.

Festercreep enters the battlefield with a +1/+1 counter on it.
, Remove a +1/+1 counter from Festercreep: All other creatures get -1/-1 until end of turn.

You gain 10 life. Then if you have more life than an opponent, create a 5/5 white Giant Warrior creature token.

Flying
When Final-Sting Faerie enters the battlefield, destroy target creature that was dealt damage this turn.

Whenever Fire Juggler becomes blocked, clash with an opponent. If you win, Fire Juggler deals 4 damage to each creature blocking it. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher converted mana cost.)