From Lost Temple Traders:

"We’re all a little mad! Introducing the Zombie Hatter Mug designed for Lost Temple Traders by Bridget McCarty. The Zombie Hatter stands 6” tall.

Produced by Munktiki Imports." & also "Our Zombie Hatter mug by Bridget McCarty has been vandalized by the one and only FAUST! This run is limited to just 12 pieces and will ship this week! "

The hat has "10/6" written on it. The 10/6 refers to the cost of a hat — 10 shillings and 6 pence, and later became the date and month to celebrate Mad Hatter Day.