Is there a single word for 'scaring a person for sake of fun'?

An example situation:

My friend is watching a horror movie. He is lost deep into the movie. Taking advantage of this situation I wear a mask of a ghost and suddenly appear in front of him just to scare him for the sake of fun.

Does the act I did ie. 'scaring a person for sake of fun' have a single word equivalent?

To my mind this sounds like spooking someone i.e. you put on the mask and spooked your friend.

Perhaps too specific for all the situations you might want this word for, but 'prank' is one word that leaps to my mind.

To play a practical joke on someone.

A practical joke is a mischievous trick played on a person, especially intended to make the victim appear foolish and experience embarrassment or discomfort.

The person doing the act is called a "practical joker."

I'd say "tease" is a basic word which covers most of the sense of what you're describing.

There are other words for it too, but they aren't family-friendly. :) You would probably hear them from your friend if you did something like this.