Porcelain is a delicate solid material used for the construction of various objects.
Guybrush's Phobia
Guybrush Threepwood was known to have a phobia of porcelain.
It is quite clear that whatever the cause of this phobia was, was something that happened during his time trapped in the Carnival of the Damned.
He first mentioned his fear after his cursed proposal to Elaine Marley, though during his quest for Big Whoop he was quite comfortable handling it.
Appearances
SMI
Threepwood can use a porcelain vase in Marleys Mansion to hit over the head of Fester Shinetop.
MI2
Threepwood can buy a Rock and Roll Collectors Plate, and ask to buy a Porcelain Vase from the Booty Boutique.