Joyrock

Joyrock (ジョイロック) is a low-ranking mazoku that appears in Slayers: The Motion Picture. He is voiced by 玄田哲章 Tesshō Genda.

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.

Lina travelled back in time to confront Joyrock before it killed the elves. Teaming up with Rowdy Gabriev, who wielded the Sword of Light, she was able to slay the demon.