Why shouldn't you “write like with a chicken's leg”?
An illegible note can be disapprovingly described as “написал, как курица лапой” (“napisal, kak kuritsa lapoy” or “written like with a chicken's leg”).
This expression has Latin roots. The ancient Roman playwright Plautus, in his works, compared parchments and tablets with illegible inscriptions to the marks left on the ground by poultry. "Gallina scripsit" made its way into other languages, including Russian. In our culture, this ironic remark has become even more poignant. Vladimir Dahl's collection of proverbs and sayings includes the following variation: "The writing looks like chickens had scrawled it." However, over time, it has evolved into the more prosaic: "To write like with a chicken's leg."