Mekurabe

Mekurabe (Japanese: 目競or めくらべ, meaning "staring contest") are giant mounds of skulls and severed heads which stare at people in Japanese mythology. They begin as masses of individual skulls, which roll around and around. Eventually they clump together and form into a massive skull-shaped mound.

A LTERNATE NAMES : dokuro no kai (the phenomenon of skulls)

Myths & Legends
Taira no Kiyomori, the young general who had just recently conquered all of Japan, stepped out into his garden one morning to see an uncountable number of skulls rolling about, glaring at him. The surprised Kiyomori called for his guards, but nobody heard him.

As Kiyomori watched, the skulls began to gather together in the middle of the garden. They clumped together, rolling up on top of each other, and formed a single giant mass. The pile of skulls was shaped like an enormous skull close to 45 meters in size.

The mass of skulls glared at Kiyomori out of its countless eye sockets. Kiyomori took a breath and steadied himself. He glared back at the skulls with all of his resolve.

Finally, the mass of skulls crumbled apart. The skulls melted like a snowflake in the sun, and vanished without a trace.

Interactions
Mekurabe are only known for doing one thing: staring at people. If you win the staring contest, the skulls will vanish without a trace. If you lose the staring contest, what happens is not recorded.

Origin
Mekurabe are famously described in  The Tale of the Heike. Their name was invented later during the Edo Period, and mekurabe appears in Toriyama Sekien’s  Konjaku hyakki shūi.