The name Algol derives from Arabic رأس الغول ra's al-ghūl : head (ra's) of the ogre (al-ghūl) (see "ghoul"). The English name Demon Star is a direct translation.
In Hebrew folklore it was known as Rōsh ha Sāṭān 'Satan's Head', via Edmund Chilmead, who called it 'Divels head' or Rosch hassatan. A Latin term from the 16th century was Caput Larvae 'Spectre's Head'. It was also linked with Lilith. Hipparchus and Pliny made this a separate, though connected, constellation.
It is known as 大陵五 (the Fifth Star of the Mausoleum) in Chinese astronomy, and also bore the grim name Tseih She (叠尸 - die2 shi1 in Modern Pinyin), meaning 'piled up corpses'.
This I did not know, being an astronomy geek and all. Kool stuff