While a lot of practical jokes are, it's for sure possible to do practical jokes that I'd file under harmless fun. The tv program Just for laughs is --somewhat surprisingly-- really good at this. Excuse the awful laugh track and jaunty music, but a good example is how they turned an air horn prank into something fairly harmless: https://www.youtube.com/watch?v=Mb2VZ6lp8f0
I wouldn't call the gentle deception of something like temporarily taking a plastic apple from a close co-worker's cubicle shelf and replacing it each day with a larger and larger apple "bullying". The premise of this movie is absolutely trashy, but I think good-natured practical joking is at least possible.