Joyrock first appears in a small, frog-like form. He later takes a much larger humanoid form, though still possessing reptilian features.
In the past, Joyrock attacked Mipross Island, killing the elves who inhabited it. Many years later, Lina Inverse and Naga the Serpent visited Mipross. They attempted to slay Joyrock; however, the mazoku had grown too powerful from its slaughter of the elves to be defeated by Lina's Dragon Slave.