This guy here is Mona (aka Monā, Moner, or Monar)! He is the most guy of 2chn, if not one of the top guys of all time. He's representative of a generic Japanese person/2channel user. His friends are Moralar, Giko, and Shii.
This is the rear end of Mona. Notice his cute round tail. We call him a cat, but he's technically part cat part bear. Don't ask me how that works biologically.
Mona is thought to have originated on either Ayashii World or Amezou, which were both precursors to 2ch. He looked more bearlike then, and his catchphrase was "おまえらも暇な奴らだなぁ""omae-ra mo himana yatsurada nā", translating to "You guys have too much spare time", a saying used to remind internet users to go touch grass.
Then someone replied to a Mona with another Mona saying "マエモナー"/"omae mona", meaning, "So do you!" or "Look who's talking!" That instantly became Mona's new catchphrase.
