The AxiDraw itself does not have any built-in fonts. The AxiDraw uses system-installed truetype fonts, which can include Greek fonts, if they are installed on your computer.
Not to hijack NIKOS post but on the subject of fonts, if I type it out in Adobe Illustrator using let’s say a Chinese font for example and convert to paths and SVG, could I import it into Inkscape and AxiDraw can handle it?