Spectral Cards are a form of consumable you can obtain during a run.
Spectral Cards are similar to Tarot Cards in the sense that they generally modify the playing cards in the deck as well, though to a much greater extent than Tarot Cards. In exchange for these large modifications, they usually disadvantage the player in another aspect of gameplay, such as reducing hand size, destroying additional cards or consuming all money. There are 18 different cards with no unlock conditions, but they can usually only be found in booster packs and not individually. It is possible to spawn Spectral Cards via certain Jokers, or, in certain circumstances, purchase them in the shop, in which case they will take up a Consumable slot.
Adds a Foil, Holographic, or Polychrome edition (determined at random) to 1 selected card in hand.
Wraith
Creates a random Rare Joker (must have room), but sets money to $0.
Sigil
Converts every card in your hand to a single, random Suit.
Ouija
Converts every card in your hand to a single, random Rank, but reduces total hand size by 1.
Ectoplasm
Adds Negative to a random Joker, but reduces total hand size by 1. (Hand size reduction on use increases by 1 for every time Ectoplasm is used in a run, eg. using Ectoplasm 3 times in the same run decreases hand size by a total of 6 (1+2+3))
Immolate
Destroys 5 random cards in hand, but gain $20.
Ankh
Creates a copy of 1 of your Jokers at random, then destroys the others, leaving you with two identical Jokers. (Editions are also copied, except Negative)
Artwork: This card is animated, with the gem beating like a heart, or perhaps something inside is trying to break out...
Black Hole
Upgrades every poker hand (including secret hands not yet discovered) by one level.
Trivia[]
Familiar, Grim, Immolate, Incantation, Sigil, and Ouija cannot be used when your hand size is 1.
Hex cannot be used when all your Jokers already have an Edition.
Wraith will always set your money to $0 even when in the negatives, removing the debt completely.
Aura has a 50% chance to make a card Foil, a 35% chance to make a card Holographic, and a 15% chance to make a card Polychrome. These are the same odds that Wheel of Fortune has when upgrading a Joker, given that Wheel of Fortune triggers.
Eternal Jokers cannot be destroyed by Hex or Ankh.
The art of Black Hole appears to be pulling in the sides of the card and its own name tag towards the center by the force of its gravity.
Sixth Sense and 
SĆ©ance, or found in the shop when using the 
Ghost Deck.
