You may have Clone enter the battlefield as a copy of any creature on the battlefield.

Flying

Cloud Elemental can block only creatures with flying.

Flying

Whenever Conundrum Sphinx attacks, each player chooses a card name. Then each player reveals the top card of their library. If the card a player revealed has the name they chose, that player puts it into their hand. If it doesn't, that player puts it on the bottom of their library.

Target creature has base power and toughness 1/1 until end of turn.

Counter target red or green spell.

Scry 4, then draw two cards.

Whenever Frost Titan becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.

Whenever Frost Titan enters the battlefield or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Harbor Serpent can't attack unless there are five or more Islands on the battlefield.

Enchant creature

Enchanted creature can't attack or block, and its activated abilities can't be activated.

When enchanted creature becomes the target of a spell or ability, destroy Ice Cage.

+2: Each player draws a card.

−1: Target player draws a card.

−10: Target player mills twenty cards.

Whenever you draw a card, you may have target player mill a card.

Draw three cards.

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.

You may cast spells as though they had flash.

Counter target spell unless its controller pays {3}.

Exile all creatures you control, then reveal cards from the top of your library until you reveal that many creature cards. Put all creature cards revealed this way onto the battlefield, then shuffle the rest of the revealed cards into your library.

Other Merfolk creatures you control get +1/+1.

{T}: Target Merfolk creature can't be blocked this turn.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Whenever Merfolk Spy deals combat damage to a player, that player reveals a card at random from their hand.

Enchant creature

You control enchanted creature.

Counter target noncreature spell.

When Phantom Beast becomes the target of a spell or ability, sacrifice it.

Scry 2, then draw a card. (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.)

You may choose new targets for target spell.

Whenever Scroll Thief deals combat damage to a player, draw a card.

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

All lands are Islands in addition to their other types.

Creatures without flying or islandwalk can't attack.

Each player shuffles their hand and graveyard into their library, then draws seven cards. Exile Time Reversal.

Target player mills five cards.

Target player mills half their library, rounded down.

Return target creature to its owner's hand.

Defender

Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

{U}: Water Servant gets +1/-1 until end of turn.

{U}: Water Servant gets -1/+1 until end of turn.

Destroy target tapped creature.

First strike (This creature deals combat damage before creatures without first strike.)

Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)

Each opponent loses 3 life. You gain life equal to the life lost this way.

Sacrifice a creature: Bloodthrone Vampire gets +2/+2 until end of turn.

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Other Vampire creatures you control get +1/+1.

Tap five untapped Vampires you control: Gain control of target creature. It becomes a Vampire in addition to its other types.

Lifelink

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Destroy target green or white creature.

You may pay 6 life and sacrifice three black creatures rather than pay this spell's mana cost.

Flying, trample

Search your library for a card, put that card into your hand, then shuffle.

Return target creature card from your graveyard to your hand.

Destroy target nonblack creature.

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.