I love that you don't seem to find a ton of these TB skulls in collections, but the other Tiki Bob is there and more sought after.
Tiki Mug Design
Tiki Bob's Skull Mug
in 8 collections
This nice, off-white skull mug comes from Tiki Bob's in San Francisco, and is marked as such. Hollow area behind eye sockets, nose, and three missing teeth.