Cedric appeared as a ghost several years after Hogwarts is rebuilt and like the true Hufflepuff he is, spends his time helping students with their homework and keeping an eye out for teachers and prefects while pranksters set up their stuff. Sometimes he’ll even talk about the Triwizard Tournament, if you catch him in a thoughtful mood.

after a prank war gets started up between gryffindor house and slytherin house, some of the muggleborn slytherins have their mum owl them their slenderman morphsuit and they sit outside in the setting sun staring up at the gryffindor tower every night for a month and it terrifies all the gryffindors so badly that prank war ends for the year.