Maybe not pranking as such. Perhaps getting them to reluctantly crack a smile and feel a grudging admiration for their parents
I am feeling smug. This morning I logged into Netflix and changed all their profile names to suitably 
pet names. I am eagerly awaiting the reactions which will happen the minute they get to their bedrooms when they get home later. I was going to change the WiFi password to something similar but couldn't work out how to do it 
Have also had success with waiting until they're asleep and changing their wallpaper on their phones. Sometimes to a picture of me 
Anyone else have any ideas? We do like a bit of pranking in this house.