The Ghostly Jam is a fan-made grub that can be obtained in the Miitopia Tales DLC.
Ghostly Jam[]
It's a jar of dark purple jam surrounded by black fog. The jar's lid is red. It fills 50% of the stomach.
It's considered to be a Very Rare grub much like certain grub like Cheesecake. As this is a unique grub obtained from a tale, it's immediately transferred to the main story after the stage featuring the monster that drops it is cleared once (per tale playthrough), rendering it unusable by the tale's main character unlike other grub.
Description[]
Despite the sinister-looking fog, the jam itself is actually very tasty.