They were reputed to wear trousers made from the skins of their enemies. But its the craftsmanship and sheer bulk of their gold ornaments that catches most peoples’ attention. As far as “mare milkers” (what some Greeks called them) being an insult, the Mongols did likewise and still do. Warrior horse cultures separated by a thousand years roaming some of the same wide spaces.
As I recall their name meant “skinners”. They did indeed flay or scalp, and made drinking cups of the skulls of enemies. The brain pan, not the face. https://books.google.com/books?id=l8Uy2k1srAIC&pg=PA83&lpg=PA83&dq=scythian+skull+cup&source=bl&ots=jBknx2Dpvk&sig=Tc5uN9CSglA9iWbzkBy1E9HkIh0&hl=en&sa=X&ved=0ahUKEwifuIi36ufNAhWE3SYKHWa_AN0Q6AEIQzAI#v=onepage&q=scythian%20skull%20cup&f=false