Sadist

People who commit acts of Sadism and masochism are called sadists and masochists respectively, for further information on the subject see the accompanying article: Sadomasochism

Some subjects sadist could represent are: Sadist (band), an Italian progressive death metal band
"Sadist", a song by that band from their album Above the Light
Sadist (album), their self-titled album
"Sadist", a different song by that band on the above album
Sadistic personality disorder, a mental disorder

Some other non-direct subjects sadist could represent are: Sadism and masochism as medical terms
Sadistik Exekution, an Australian death metal band