Slithermuse

When this creature leaves the battlefield, choose an opponent. If that player has more cards in hand than you, draw cards equal to the difference.
Evoke {3}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Glimmerbell

Maze Glider

Flying
Multicolored creatures you control have flying.

Tidewalker

This creature enters with a time counter on it for each Island you control.
Vanishing (At the beginning of your upkeep, remove a time counter from this creature. When the last is removed, sacrifice it.)
Tidewalker's power and toughness are each equal to the number of time counters on it.

Air Elemental

Floodhound

{3}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Tidewater Minion

Defender (This creature can't attack.)
{4}: This creature loses defender until end of turn.
{T}: Untap target permanent.

Brine Elemental

Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, each opponent skips their next untap step.

Vaporkin

Flying
This creature can block only creatures with flying.

Scaldkin

Flying
{2}{R}, Sacrifice this creature: It deals 2 damage to any target.

Soul of the Rapids

Flying
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Watercourser

{U}: This creature gets +1/-1 until end of turn.

Whimwader

This creature can't attack unless defending player controls a blue 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.

Sea Spirit

{U}: This creature gets +1/+0 until end of turn.

Aquamoeba

Discard a card: Switch this creature's power and toughness until end of turn.

Updraft Elemental

Octavia, Living Thesis

This spell costs {8} less to cast if you have eight or more instant and/or sorcery cards in your graveyard.
Ward {8}
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature has base power and toughness 8/8 until end of turn.

Void Stalker

{2}{U}, {T}: Put this creature and target creature on top of their owners' libraries, then those players shuffle their libraries.

Hydromorph Guardian

{U}, Sacrifice this creature: Counter target spell that targets a creature you control.

Cloudkin Seer

Flying
When this creature enters, draw a card.

Question Elemental?

Did you know this creature has flying?
Are you aware that any time you say something that isn't a question, when a player points out this fact first, they gain control of this creature?

Fog Elemental

Flying (This creature can't be blocked except by creatures with flying or reach.)
When this creature attacks or blocks, sacrifice it at end of combat.

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Subtlety

Flash
Flying
When this creature enters, choose up to one target creature spell or planeswalker spell. Its owner puts it on their choice of the top or bottom of their library.
Evoke—Exile a blue card from your hand.

Yarok's Wavecrasher

When this creature enters, return another creature you control to its owner's hand.

Water Elemental

Nimbus of the Isles

Flying (This creature can't be blocked except by creatures with flying or reach.)

Storm Elemental

Flying
{U}, Exile the top card of your library: Tap target creature with flying.
{U}, Exile the top card of your library: If the exiled card is a snow land, this creature gets +1/+1 until end of turn.

Interdisciplinary Mascot

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Ward {3}
When this creature enters, look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

Hydromorph Gull

Flying
{U}, Sacrifice this creature: Counter target spell that targets a creature you control.

Air-Cult Elemental

Flying
Whirlwind — When this creature enters, return up to one other target creature to its owner's hand.

Bubble Up

Put target instant or sorcery card from your graveyard on top of your library. (Then exile this card. You may cast the creature later from exile.)

Aquatic Alchemist

Whenever you cast your first instant or sorcery spell each turn, this creature gets +2/+0 until end of turn.

Aquatic Alchemist // Bubble Up

Supreme Exemplar

Flying
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Living Tsunami

Flying
At the beginning of your upkeep, sacrifice this creature unless you return a land you control to its owner's hand.

Talonrend

Flying
{U/R}: This creature gets +1/-1 until end of turn.

Thassa's Devourer

Constellation — Whenever this creature or another enchantment you control enters, target player mills two cards.

Risen Riptide

Whenever you cast a kicked spell, this creature has base power and toughness 5/5 until end of turn.

Thousand Winds

Flying
Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, return all other tapped creatures to their owners' hands.

Thunder Drake

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control this creature.

Air Servant

Flying
{2}{U}: Tap target creature with flying.

Cyclone Sire

Flying
When this creature dies, you may put three +1/+1 counters on target land you control. If you do, that land becomes a 0/0 Elemental creature with haste that's still a land.

Frost Walker

When this creature becomes the target of a spell or ability, sacrifice it.

Brackwater Elemental

When this creature attacks or blocks, sacrifice it at the beginning of the next end step.
Unearth {2}{U} ({2}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Living Tempest

Wave Elemental

{U}, {T}, Sacrifice this creature: Tap up to three target creatures without flying.

Quicksilver Elemental

{U}: This creature gains all activated abilities of target creature until end of turn. (If any of the abilities use that creature's name, use this creature's name instead.)
You may spend blue mana as though it were mana of any color to pay the activation costs of this creature's abilities.

Blizzard Elemental

Tidal Force

At the beginning of each upkeep, you may tap or untap target permanent.

Water Servant

{U}: This creature gets +1/-1 until end of turn.
{U}: This creature gets -1/+1 until end of turn.

Wind Spirit

Flying
Menace (This creature can't be blocked except by two or more creatures.)

Phase Dolphin

Whenever this creature attacks, another target attacking creature can't be blocked this turn.

Frostfist Strider

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When this creature enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Nevermaker

Flying
When this creature leaves the battlefield, put target nonland permanent on top of its owner's library.
Evoke {3}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Time Elemental

When this creature attacks or blocks, at end of combat, sacrifice it and it deals 5 damage to you.
{2}{U}{U}, {T}: Return target permanent that isn't enchanted to its owner's hand.

Novellamental

Glacial Crasher

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
This creature can't attack unless there is a Mountain on the battlefield.

Floodchaser

This creature enters with six +1/+1 counters on it.
This creature can't attack unless defending player controls an Island.
{U}, Remove a +1/+1 counter from this creature: Target land becomes an Island until end of turn.

Cavalier of Gales

Flying
When this creature enters, draw three cards, then put two cards from your hand on top of your library in any order.
When this creature dies, shuffle it into its owner's library, then 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.)

Benthicore

When this creature enters, create two 1/1 blue Merfolk Wizard creature tokens.
Tap two untapped Merfolk you control: Untap this creature. It gains shroud until end of turn. (It can't be the target of spells or abilities.)

Plasma Elemental

Guile

This creature can't be blocked except by three or more creatures.
If a spell or ability you control would counter a spell, instead exile that spell and you may play that card without paying its mana cost.
When Guile is put into a graveyard from anywhere, shuffle it into its owner's library.

Vortex Elemental

{U}: Put this creature and each creature blocking or blocked by it on top of their owners' libraries, then those players shuffle.
{3}{U}{U}: Target creature blocks this creature this turn if able.

Zephyr Winder

Flying
Whenever this creature deals combat damage to a player, untap up to one target creature.

Boreal Elemental

Flying
Spells your opponents cast that target this creature cost {2} more to cast.

Thundercloud Elemental

Flying
{3}{U}: Tap all creatures with toughness 2 or less.
{3}{U}: All other creatures lose flying until end of turn.

Tideforce Elemental

{U}, {T}: You may tap or untap another target creature.
Landfall — Whenever a land you control enters, you may untap this creature.

Aeromoeba

Flying
Discard a card: Switch this creature's power and toughness until end of turn.

Shorecrasher Elemental

{U}: Exile this creature, then return it to the battlefield face down under its owner's control.
{1}: This creature gets +1/-1 or -1/+1 until end of turn.
Megamorph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Frost Lynx

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

Aethersnipe

When this creature enters, return target nonland permanent to its owner's hand.
Evoke {1}{U}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Stormwing Entity

This spell costs {2}{U} less to cast if you've cast an instant or sorcery spell this turn.
Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, scry 2.

Waterspout Elemental

Kicker {U} (You may pay an additional {U} as you cast this spell.)
Flying
When this creature enters, if it was kicked, return all other creatures to their owners' hands and you skip your next turn.

Chillbringer

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

Ethereal Forager

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying
Whenever this creature attacks, you may return an instant or sorcery card exiled with this creature to its owner's hand.

Cloud Elemental

Embodiment of Spring

{1}{G}, {T}, Sacrifice this creature: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Ethereal Whiskergill

Flying
This creature can't attack unless defending player controls an Island.

Eon Frolicker

Flying
When this creature enters, if you cast it, target opponent takes an extra turn after this one. Until your next turn, you and planeswalkers you control gain protection from that player. (You and planeswalkers you control can't be targeted, dealt damage, or enchanted by anything controlled by that player.)

Dreamtail Heron

Mutate {3}{U} (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
Whenever this creature mutates, draw a card.

Living Conundrum

Hexproof
If you would draw a card while your library has no cards in it, skip that draw instead.
As long as there are no cards in your library, this creature has base power and toughness 10/10 and has flying and vigilance.

Primal Plasma

As this creature enters, it becomes your choice of a 3/3 creature, a 2/2 creature with flying, or a 1/6 creature with defender.

Wave-Wing Elemental

Flying
Landfall — Whenever a land you control enters, this creature gets +2/+2 until end of turn.

Waterkin Shaman

Whenever a creature you control with flying enters, this creature gets +1/+1 until end of turn.

Scion of Glaciers

Splashy Spellcaster

Whenever you cast an instant or sorcery spell, create a Sorcerer Role token attached to up to one other target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has "Whenever this creature attacks, scry 1.")

Willow-Wind

Flying
When this creature enters, scry 2.

Chakram Retriever

Partner with Chakram Slinger (When this creature enters, target player may put Chakram Slinger into their hand from their library, then shuffle.)
Whenever you cast a spell during your turn, untap target creature.

Icewrought Sentry

Vigilance
Whenever this creature attacks, you may pay {1}{U}. When you do, tap target creature an opponent controls.
Whenever you tap an untapped creature an opponent controls, this creature gets +2/+1 until end of turn.

Glacial Stalker

Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)