With apologies to Neandermagnon if I'm wrong 
Neandermagnon is my guess.
My only other guess is Admin! With same apologies qualification
It wasn't me (at least, I don't recall ever knowing that fact never mind writing about it, though my memory's crap.... lol), but I'm honoured that you thought of me
It reminds me of this time in A-level French (year 12-13) when someone put all the French books on the picture rail in the classroom (yeah, weird classroom decor...) and the French teacher was totally convinced it was me and I said "I agree it's the sort of thing I would've done but it really, honestly wasn't me" while wishing I had thought of it. My French teacher of course did not believe me at all, but had sufficient sense of humour not to want to punish anyone over it.
(I found out a day or two later that it was the German A-level class that did it.)
Oh, I do beg your pardon. It's just what they call themselves. (Also I'm old and forgetful...)
In my silly schooldays back in the late 1940s I once rigged up a thread that ran up the wall from my back row desk, along to the front of class wall via drawing pins in the picture rail, then along the picture rail above the wall-width blackboard to the centre, where it dropped down behind the blackboard. When I pulled the thread, an A3 size paper rose above the blackboard until I released the thread when the paper disappeared again.
One teacher was known for repeating a particular phrase, and when class started on this particular day, the first couple of times they said it, the class dissolved in muffled hysterics from the sign with the same phrase appearing for a moment behind the baffled teacher, who couldn't understand the reason for the amusement.
I didn't get caught because I only did it three times and then left the sign concealed despite the urge to show it again.
That is quite an epic level of pranking