a prank
A prank is when you trick someone in a clever way and it's the best part of your day.
I put a whoopee cushion on my principal's chair and he yelled 'what the hell!' and then he got mad.
I took my brother's favorite shoes and put them in the freezer, and he was so mad he tried to eat them.
I told my friend that her dog was missing and she cried for 20 minutes.