you can buy them for $19.99 from Mwave:
Mwave.com.au - Pac-Man Glossary Heat Change Mug
Pac-Man Glossary Heat Change Mug
Pac Man Glossary Heat Change Mug.
The icons of the game appear before your eyes when you add a hot drink to the mug.
Packed in a matching cardboard display box.
Not suitable for microwave or dishwasher use.
Size: 9.5cm x 8.5cm.
The PAC-MAN™ Glossary Heat Change Mug is a great gift for all PAC-MAN fans and anyone who loves retro arcade games. It is a standard sized, stoneware mug with heat change properties so the image on the outside of the mug changes when you fill it with a hot beverage.
When you first look at the Glossary Heat Change Mug without any hot liquid in, it is just a plain black mug bearing the PAC-MAN logo. Pour in coffee or tea and the sides of the mug begin to fill up with images of all the PAC-MAN characters and icons. The mug features not just PAC-MAN and the ghosts (whose names are also included) but the types of fruit and other power sources PAC-MAN is able to eat and the number of points each is worth. There may be some characters that even the most dedicated of players may not be familiar with and the PAC-MAN™ Glossary Heat Change Mug will fill any gaps in your knowledge.