You allow Jester to examine your Seven of Hands.
Jester tells you, "Oh goody, you found one. Come back when you have the whole deck."
The cards are givable/tradable. Repeat cards can also be exchanged by giving a Jester's Token to a Casino owner then giving the repeat to the High Stakes NPC, who will give you a random card in return.
Part of the Jester's Cards quest, the cards that make up the Deck of Hands are:
King of Hands
Queen of Hands
Jack of Hands
Ten of Hands
Nine of Hands
Eight of Hands
Seven of Hands
Six of Hands
Five of Hands
Four of Hands
Three of Hands
Two of Hands
Ace of Hands
Combine the cards in order, from Ace to King:
Besides the cards of hands, there is also a jester card. This acts as a "joker", so can be used for every missing card in the deck.
Verified to drop off the following creatures:
See also Deck of Eyes.