A person who is a Narcissist has a mental condition in which the person has an inflated sense of their own importance, a deep need for excessive attention and admiration, troubled relationships, and a lack of empathy for others.
Some signs that someone is a Narcissist are.
Superiority and entitlement, Exaggerated need for attention and validation, Perfectionism, Great need for control, Lack of responsibility, blaming and deflecting, Lack of boundaries, Lack of empathy and Emotional reasoning.
If you notice any of those signs in a person then you're likely dealing with a Narcissist.