The word millipede literally means a creature with a thousand legs.
They are arthropods with many legs, although less then a thousand. I took these pictures in Hungary in a meadow in a nature reserve. It is likely to be a Megaphyllum Unilineatum but I cannot be certain. Neither the picture quality nor the information I was able to find gives any certainty to make a positive ID.
Millipedes are usually harmless detrivores, but they do produce nasty smelling chemicals for defense. Apparently in some places they show up in such large numbers as to become a nuisance.