Frost Trickster

Flying
When Frost Trickster enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Starlit Mantle

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature you control
When Starlit Mantle enters, enchanted creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
Enchanted creature gets +1/+1.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Augur of Bolas

When Augur of Bolas enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Academy Journeymage

This spell costs {1} less to cast if you control a Wizard.
When Academy Journeymage enters, return target creature an opponent controls to its owner's hand.

Pestermite

Flash
Flying
When Pestermite enters, you may tap or untap target permanent.

Island

Chilling Trap

Target creature gets -4/-0 until end of turn. If you control a Wizard, draw a card.

Faerie Seer

Flying
When Faerie Seer enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Voracious Greatshark

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, counter target artifact or creature spell.

Remand

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard.
Draw a card.

Aether Channeler

When Aether Channeler enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Expedition Diviner

Flying
As long as you control another Wizard, Expedition Diviner has "When this creature dies, draw a card."

Undersea Invader

Flash (You may cast this spell any time you could cast an instant.)
Undersea Invader enters tapped.

Thriving Isle

Thriving Isle enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When Capture Sphere enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Opportunity

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Stinging Lionfish

Whenever you cast your first spell during each opponent's turn, you may tap or untap target nonland permanent.

Thryx, the Sudden Storm

Flash (You may cast this spell any time you could cast an instant.)
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Starlight Snare

Enchant creature
When Starlight Snare enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Delightful Discovery

This spell costs {1} less to cast for each spell your opponents have cast this turn.
Scry 2, then draw two cards. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Naban, Dean of Iteration

If a Wizard you control entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.