With regards to Robin Hood; For my sins! I produced three medieval Robin Hood plays. Robin of the dramas was nothing like the charming hero of my girlhood. He was a guy who hung out in the woods and picked fights, which he generally won. No robbing rich, no giving to the poor. Blessedly we didn't find out we had the bowdlerized version of "Robin Hood And The Monk" until our last rehearsal. Friar Tuck ends the play by reciting a naughty little rhyme about Maid Marian. We were fed up with the girl who played the role, but Friar Tuck wasn't what you'd call a quick study.
Beatrix Potter wrote a story called "The Fairy In The Oak", which begins with the country proverb, "Fairy folks is in old oaks."
Don't the Brits celebrate Oak Apple Day, in honor of King Charles' escape? I remember a song from John Roberts and Tony Barrand's album or spring carols, "Now we do bring you the royal branch of oak. God bless our king and queen and all the royal folk."