The famous Star Carr headdress, from the Mesolithic, c. 8.000 BC. BM London.
Around 20 similar finds are known, e.g. from Biesdorf, Hohen Viecheln, Königshoven, Plau and Poggenwisch. They have been interpreted as camouflage worn by hunters, but also as paraphernalia of shamans.

The interpretation as part of the costume of shamans is very much based on historic analogies. Here is the earliest known western depiction of a Siberian shaman wearing a similar headdress, by Nicholaes Witsen (17th century, public domain).

For another famous shaman with an elaborate dress have a look here: https://twitter.com/museumhalle/status/1243545459416842246?s=21 https://twitter.com/museumhalle/status/1243545459416842246