Who: Beholder
Metal
Because Beholder is a quite popular monster in Dungeons&Dragons, it happened there are at least three bands with the name Beholder.
1) An Italian power metal band with both male and female vocals, now disbanded.
2) A UK heavy metal tribute band.
3) Spanish rock/heavy metal band with its best known album Espiritu del fuego (the video Lucharé hasta el fin belongs to them).