Minecraft developer Mojang has added a new member to its deliberately small development team, announcing that Henrik Pettersson has joined the staff as a graphical artist.The announcement was made via the personal Twitter account of Mojang founder Markus Persson on Monday.Pettersson specializes in 2D art, which he will contribute to Mojang's Scrolls, according to a post on his Twitter account this morning.Prior to Mojang, Pettersson was at Fabrication Games , working on titles that include 2D platformer Un Juego de Huevos for the Zeebo , a low cost download-only console developed for emerging markets. Fabrication also developed iOS titles Bug Fest and Free Zombie Hero: Kill Angry War Ninja, among others.Mojang's popular Minecraft recently surpassed over 3 million sales. The game is set to have a specialized convention in Las Vegas later this year.Despite its success, Mojang has remained intentionally small: its staff headcount is still under twenty, by all accounts.