According to the film, Casper was a twelve-year-old boy living in Whipstaff Manor with his inventor father J.T. McFadden until he died from pneumonia after playing out in the cold until it was past nightfall.

How did Casper's mom die?

As it turns out, TV Over Mind notes that Casper’s mom died during childbirth, leaving her husband to care for Casper alone. Later on, fans see Casper helping Kat go through the attic for something to wear to her Halloween party, and she begins trying on his mother’s clothes.

Why is Casper's dad not a ghost?

McFadden obtained medical help for Casper, but it was to be in vain, for his son’s condition was too severe to cure. Casper then passed away, leaving his father devestated. Not wanting him to be alone, Casper refused to cross over into the afterlife and returned to his father as a ghost.