Oni - Inspired by traditional Japanese tattoos. It is an illustration of an "Oni" (鬼) - like a Japanese demon (yōkai), it is a supernatural ogre or a troll in Japanese folklore. Oni are popular characters in Japanese art, literature, and theatre. The “Oni” tattoo is also quite popular in the Yakuza group and in my opinion, it fits pretty well to the T side, on the glock weapon.