Z. longissimus hatches at around 30 cm (11.8 in). Adults are usually from 110 cm (43.3 in) to 160 cm (63 in) in total length (including tail), but can grow to 200 cm (79 in), with the record size being 225 cm (7.38 ft).[3] Expected body mass in adult Aesculapian snakes is from 350 to 890 g (0.77 to 1.96 lb).[4][5] It is dark, long, slender, and typically bronzy in colour, with smooth scales that give it a metallic sheen.