Medicinal leech  (Hirudo medicinalis)

This animal has a slightly flattened cylindrical body, divided into 33 or 34 segments. The upperside is dark brown or black with six long reddish stripes, whilst the underside is speckled. There is a disc-shaped sucker at the head end. The leech is famous for sucking blood and the 'mouth' of the animal is situated within the sucker, complete with teeth. The leech also has five pairs of eyes.