You may exert Hydra Trainer as it attacks. When you do, target creature gets +X/+X until end of turn, where X is the number of counters on permanents you control. (An exerted creature won't untap during your next untap step.)

: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

Enchant creature

When Hydra's Growth enters, put a +1/+1 counter on enchanted creature.

At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

As Hydroelectric Laboratory enters, you may pay 3 life. If you don't, it enters tapped.

: Add .

Target land becomes a 3/3 Elemental creature with flying until end of turn. It's still a land.

Attacking creatures get -2/-0 until end of turn.

Draw a card.

Flying

, Sacrifice Hydromorph Gull: Counter target spell that targets a creature you control.

Whenever you tap an untapped creature an opponent controls, you may pay . When you do, choose one —

• Create a 4/4 white and blue Elemental creature token.

• Put a +1/+1 counter on each creature you control.

• Scry 2, then draw a card.

Put target creature card from a graveyard onto the battlefield under your control.

Suspend 3—

Starting with you, each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield. Repeat this process until no one puts a card onto the battlefield.

Flying, haste

You may cast sorcery spells as though they had flash. (You may cast them any time you could cast an instant.)

Kicker (You may pay an additional as you cast this spell.)

Target player discards a card. If this spell was kicked, that player discards three cards instead.

Target creature perpetually gets -2/-0.

Target creature gets -2/-0 until end of turn.

Flying

Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Whenever you crank Hypnotic Swirly Disc, target player mills X cards, where X is the number of creatures you control.

, Discard a card: Prevent the next 3 damage that would be dealt to any target this turn.

, Sacrifice Hypochondria: Prevent the next 3 damage that would be dealt to any target this turn.

When Hyrax Tower Scout enters, untap target creature.

Trample

Whenever Hystrodon deals combat damage to a player, you may draw a card.

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

: Icatian Infantry gains first strike until end of turn.

: Icatian Infantry gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Vigilance

Whenever Icewrought Sentry attacks, you may pay . When you do, tap target creature an opponent controls.

Whenever you tap an untapped creature an opponent controls, Icewrought Sentry gets +2/+1 until end of turn.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Flying, vigilance

When Icingdeath, Frost Tyrant dies, create Icingdeath, Frost Tongue, a legendary white Equipment artifact token with "Equipped creature gets +2/+0," "Whenever equipped creature attacks, tap target creature defending player controls," and equip .

Tap X target creatures.

Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

When Icy Prison enters, exile target creature.

At the beginning of your upkeep, sacrifice Icy Prison unless any player pays .

When Icy Prison leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Whenever Identity Thief attacks, you may exile another target nontoken creature. If you do, Identity Thief becomes a copy of that creature until end of turn. Return the exiled card to the battlefield under its owner's control at the beginning of the next end step.

(: Add .)

Idyllic Grange enters tapped unless you control three or more other Plains.

When Idyllic Grange enters untapped, put a +1/+1 counter on target creature you control.

Trample

: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

Target spell or permanent becomes the color of your choice until end of turn.

Flying

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

: You may choose a creature card in your hand whose mana cost could be paid by some amount of, or all of, the mana you spent on . If you do, you may cast that card face down as a 2/2 creature spell without paying its mana cost. If the creature that spell becomes as it resolves has not been turned face up and would assign or deal damage, be dealt damage, or become tapped, instead it's turned face up and assigns or deals damage, is dealt damage, or becomes tapped. Activate only as a sorcery.

Flying

When Illusionary Servant becomes the target of a spell or ability, sacrifice it.

Defender, flying, first strike

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Cast this spell only if you've cast another spell this turn.

Flying

Enchant creature

You control enchanted creature.

Whenever a creature an opponent controls enters, attach Illusory Gains to that creature.

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)

Other artifact creatures you control get +2/+2 as long as you have the city's blessing.

At the beginning of each upkeep, create a 1/1 colorless Gnome artifact creature token.

When you speak in non-rhyming sentences, sacrifice I'm Rubber, You're Glue.

Say "I'm rubber, you're glue. Everything bounces off me and sticks to you": Change the target of target spell or ability that targets only you.

At the beginning of your upkeep, if you have a card in hand, return Imaginary Pet to its owner's hand.

Whenever Imaryll, Elfhame Elite attacks, it gets +X/+X until end of turn, where X is the number of other Elves you control.

You may have Imaryll assign its combat damage as though it weren't blocked.

Hosted creatures get +2/+0 and have haste.

Host (: Host target creature at this Realm. A Realm can host any number of creatures. Host only as a sorcery.)

Whenever an instant or sorcery spell you control that targets only a single creature deals damage to that creature, Imodane deals that much damage to each opponent.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Spells you cast with mana value 6 or greater have cascade.

Whenever Imperial Recovery Unit attacks, return target creature or Vehicle card with mana value 2 or less from your graveyard to your hand.

Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Improvised Weaponry deals 2 damage to any target. Create a Treasure token. (It's an artifact with ", Sacrifice this artifact: Add one mana of any color.")

Enchant creature

At the beginning of your upkeep, you may put a fuse counter on Incendiary.

When enchanted creature dies, Incendiary deals X damage to any target, where X is the number of fuse counters on Incendiary.

Incendiary Flow deals 3 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

As an additional cost to cast this spell, sacrifice an artifact.

Incendiary Sabotage deals 3 damage to each creature.

Radiance — Until end of turn, target creature and each other creature that shares a color with it gain "This creature can't block."

Haste (This creature can attack and as soon as it comes under your control.)

Madness (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Enchant permanent

Enchanted permanent has indestructible. (Effects that say "destroy" don't destroy that permanent. A creature with indestructible can't be destroyed by damage.)