When Jadelight Spelunker enters, it explores X times. (To have it explore, reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

Jagged Barrens enters tapped.

When Jagged Barrens enters, it deals 1 damage to target opponent.

: Add or .

Flying

Search your library for up to X basic land cards, where X is the number of creatures attacking you, put those cards onto the battlefield tapped, then shuffle.

Prevent all combat damage that would be dealt this turn.

, , Sacrifice another creature: Reveal cards from the top of your library until you reveal a nonlegendary creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Haste

, Sacrifice an artifact creature: Create two Treasure tokens.

, Sacrifice a noncreature artifact: Create two 1/1 colorless Construct artifact creature tokens.

, : Untap target creature.

Whenever a creature you control dies, put two eyeball counters on Jar of Eyeballs.

, , Remove all eyeball counters from Jar of Eyeballs: Look at the top X cards of your library, where X is the number of eyeball counters removed this way. Put one of them into your hand and the rest on the bottom of your library in any order.

Remove a ki counter from Jaraku the Interloper: Counter target spell unless its controller pays .

(CARDNAME isn't a spell, it's affected by summoning sickness, it's blue, and it has ": Add .")

CARDNAME enters the battlefield tapped.

CARDNAME doesn't untap during your untap step.

At the beginning of your upkeep, you may pay . If you do, untap CARDNAME.

: Add . Spend this mana only to cast creature spells with no abilities.

Creatures you control with no abilities can't be blocked by creatures with abilities.

Whenever a Zombie or Mutant you control dies, if its power was different from its base power, draw a card.

Come Fly With Me — , Sacrifice a creature: Put a +1/+1 counter on target creature you control. It gains flying until end of turn.

Double strike

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Jaws of Stone deals X damage divided as you choose among any number of targets, where X is the number of Mountains you control as you cast this spell.

, , Discard a card: Destroy target blue permanent.

, , Discard a card: Jaya Ballard, Task Mage deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

, , Discard a card: Jaya Ballard deals 6 damage to each creature and each player.

Jaya's Greeting deals 3 damage to target creature. Scry 1.

Flying, haste

Whenever Jaya's Phoenix deals combat damage to a player or planeswalker, copy the next loyalty ability you activate this turn when you activate it. You may choose new targets for the copy.

Whenever you cast a planeswalker spell, you may return Jaya's Phoenix from your graveyard to the battlefield.

When Jeering Homunculus enters, you may goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for as a sorcery.)

: Add . This mana can't be spent to pay generic mana costs.

Flying

When Jeleva, Nephalia's Scourge enters, each player exiles the top X cards of their library, where X is the amount of mana spent to cast Jeleva.

Whenever Jeleva attacks, you may cast an instant or sorcery spell from among cards exiled with Jeleva without paying its mana cost.

Flying

: Put a +1/+1 counter on Jenara, Asura of War.

Jeska, Thrice Reborn enters with a loyalty counter on her for each time you've cast a commander from the command zone this game.

0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.

−X: Jeska, Thrice Reborn deals X damage to each of up to three targets.

Jeska, Thrice Reborn can be your commander.

Partner

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.

Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

Flash (You may cast this spell any time you could cast an instant.)

Defender

When Jeskai Barricade enters, you may return another target creature you control to its owner's hand.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Whenever Jeskai Elder deals combat damage to a player, you may draw a card. If you do, discard a card.

Enchant creature

Enchanted creature gets +2/+2.

Enchanted creature has flying as long as you control a red or white permanent.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Choose one. If you control a commander as you cast this spell, you may choose both instead.

• Add for each card in target opponent's hand.

• Exile the top three cards of your library. You may play them this turn.

Jester's Mask enters tapped.

, , Sacrifice Jester's Mask: Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. That player puts those cards into their hand, then shuffles.

, , Sacrifice Jester's Sombrero: Look at target player's sideboard, choose three cards from it, and remove those cards from the match.

Creatures you control get +1/+0 and have vigilance as long as you control three or more creatures.

Creatures you control also get +1/+0 and have trample as long as you control six or more creatures.

Creatures you control also get +1/+0 and have double strike as long as you control nine or more creatures.

(: Add , , or .)

Jetmir's Garden enters tapped.

Cycling (, Discard this card: Draw a card.)

Each opponent mills three cards, then you may cast a spell from each opponent's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.

, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

: Prevent the next 1 damage that would be dealt to any target this turn.

: Target creature can't be blocked this turn.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Islandcycling , swampcycling (, Discard this card: Search your library for an Island or Swamp card, reveal it, put it into your hand, then shuffle.)

Flying

Historic spells you cast cost less to cast. (Artifacts, legendaries, and Sagas are historic.)

: Regenerate target artifact creature.

Flash

At the beginning of your end step, draw seven cards.

Each opponent's maximum hand size is reduced by seven.

If you would create one or more tokens, you may instead create that many 2/2 green Cat creature tokens with haste or that many 3/1 green Dog creature tokens with vigilance.

: Until end of turn, Jodah's Avenger gets -1/-1 and gains your choice of double strike, protection from red, vigilance, or shadow. (A creature with shadow can block or be blocked by only creatures with shadow.)

You may look at the top card of your library any time.

Once each turn, you may cast an instant or sorcery spell from the top of your library. (You still pay its costs. Timing rules still apply.)

Untap up to two target creatures. They each get +2/+2 until end of turn.

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell.)

Create a 4/3 black Ogre Warrior creature token.

Target creature gets +2/+2 until end of turn. If it's paired with a creature, that creature also gets +2/+2 until end of turn.

Whenever you attack with one or more creatures with power 4 or greater, create a Treasure token.

, Sacrifice a Treasure: Jolene, Plundering Pugilist deals 1 damage to any target.

, , Discard two cards: All lands target player controls become 3/3 creatures until end of turn. They're still lands.

Shroud (This creature can't be the target of spells or abilities.)

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)