noun \ˈsā-ˌdi-zəm, ˈsa-\
>enjoyment that someone gets from being violent or cruel or from causing pain; especially : sexual enjoyment from hurting or punishing someone

Sadists are the yin to a masochists‘ yang. Sadism is the receiving of pleasure through inflicting pain on another. The term itself actually comes from the Marquis de Sade, a famous sadist who wrote novels about his sexual inclinations. Sadism is also the S in the initialism BDSM. There are plenty of examples of sadists in popular culture. Christian Grey, from the popular Fifty Shades of Grey, is a sexual sadist.