This mug is shaped like a bust of the villain, Skeletor, from the He-Man Masters of the Universe (MOTU) comics, television, and toys franchise that began in the 1980s. His evil lair, Snake Mountain, is shown on reverse.
From the MONDO website:
"Get ready to conquer Eternia … with tiki drinks in hand! Mondo presents: the mighty Skeletor Tiki mug! This menacing 20oz mug features amazing hand-carved details, showcasing both Skeletor and Snake Mountain. Snagging this Limited Edition Bone colorway is the perfect excuse to put down your Power Swords, sit back, and enjoy the view from atop Snake Mountain."
This bone glaze variant was limited to 1,000 pieces. There was also a variant in yellow and purple limited to 500 pieces and sold as a pre-order for the 2021 San Diego Comic Convention but shipping later in September 2021.