Carefully look at the rock.

Quest Text You try to determine why this is called a giant head rock by looking at the rock
from different angles and perspectives. But for some unknown reason, it's called a giant head rock.

Summary You're still curious
as to why it's called a giant head rock even though you've been
looking at it for some time now. However, it looks as if the
giant head rock is the only kind of rock in the area.