Could my friend have npd (narcissistic personality disorder)?

Why do you ask?: Truth be told, it's not really a lay person's place to go diagnosing acquaintances / activity partners. Egomaniacs and people with exaggerated needs to be admired aren't the people that most folks choose for friends, and you're not likely to help or change such a person.

It is hard to know: Without more details. What makes you think they might have this disorder? You can read more about the disorder and see if their personality fits the description, but we can't make that diagnosis online without meeting the perdon.