Paraphilia is a term that describes sexual arousal in response to sexual objects or situations which is considered abnormal or odd in some societies.
An example of a Paraphilia is necrophilia: sexual attraction to corpses.
Scientific term of a sexual fantasy/ attraction beyond what society sees as normal. Also known as sexual perversion or deviation. Usually comes from childhood abuse, anti-socialism, depression, etc.
Fetishes, sado-masochism, anal, and other disturbing shit use your imagination.