Impossible trident - Wikipedia
https://en.m.wikipedia.org/wiki/Impossible_trident
WEBAn impossible trident, [1] also known as an impossible fork, [2] blivet, [3] poiuyt, or devil's tuning fork, [4] is a drawing of an impossible object (undecipherable figure), a kind of an optical illusion. It appears to have three cylindrical prongs at one end which then mysteriously transform into two rectangular prongs at the other end.
DA: 31 PA: 11 MOZ Rank: 98