If you want a wider European context, then France's Homme de Bouc and the Roman Bacchus are good places to start.

If you're looking for Bu vocabulary then there's a ton of it in English (to mention nothing of Gaelic), far too much to list here. It can be broken down into three broad categories, though: language dealing with fear (eg. Boo!), language dealing with animals, particularly the horned herds (bovine, butcher - oboe and bugle, even, since both these instruments were made from horns), and language dealing with plants (boughs, boles - but booze is the most revealing).

The Welsh <i>bwg</i> for goblin cannot be traced beyond the 1500's and is assumed to come from the Middle English <i>bugge</i> which meant a goblin or a scarecrow and can be traced to 1395.

There's also <i>bocán</i>, which is Irish for a he-goat and <i>bocan</i> which is Irish for hobgoblin. The Irish also had a goatlike battlefield wandering being called a <i>bocanách</i>.

It is assumed that the English bugge derives from the Gaelic bocan, so why the 'experts' think the Welsh bwg comes from the English is anyone's guess (except that bugge is known in earlier English texts).

Still seems arse about tit to me.