Other forms: portents
While you might love crows, your father will shudder when he sees them if he superstitiously believes they're a portent — a sign or warning — of death.
A portent is an omen of something momentous, which can be good, but is more often negative. You can use portent to mean a magical foretelling or symbol, but you can also use it to talk about something real, the way you could describe big, dark storm clouds as a portent of a thunderstorm.