Ersatz de Faux is a Falderalian mockturtle. He owns the Faux Shop in Falderal, which can only be entered with a grain of salt. His parents, both realtors, moved to Falderal from parts unknown to make his life easier, as they believed he would be more accepted in Falderal than anywhere else. He befriended Valanice when she came into his shop. He traded her The Wit & Wisdom of Falderal for a Wooden Nickel. He also traded her a rubber chicken for the China Mask she had obtained from Fernando Bullforth. He later offered to hide Valanice from the authorities in his shop.
When Rosella arrived in Falderal, Ersatz assured her that Valanice had been acquitted of her crimes.
Ersatz de Faux is a character in King's Quest VII: The Princeless Bride.