This is a mug shaped like a cresting wave or "breaker" with ghosts throughout...and a bed of skulls below.

From LowTiki:

"Don't turn your back on the ocean!

Limited run of 13. Handmade in studio in the PNW. Each mug is hand glazed per order.

The Breaker measures approximately 6" tall 4.5" wide. It holds 20 oz of liquid."

These were released in a variety of other glaze colors as well.