AidanGreenNinja Share definition Flag A guy that knows how to use a katana.He's a derp in reality and hides it with a mask. AidanGreenNinja is a derp. AidanGreenNinja by RandomeGuy666 January 24, 2020 0 0 Get merch Get the AidanGreenNinja mug. Buy Now — $32.95 See more merch