Robert was a friend to Arthur Spiderwick. It's assumed he was simply a writer friend or correspondent to Arthur, although it's possible that he was a relative of Constance Spiderwick.
Apparently, he was a pilot at the Royal Air Force in the U.K., but he lived in USA. He was also interested in Arthur's studies, at least more than Arthur's wife.
- Dear Arthur,
- Considering what you told me of your studies, I thought you'd enjoy hearing some of the stories the boys at the Royal Air Force tell about a creature that interferes with the plane's mechanics. They call the chap a gremlin.
- One of the pilots told his writer friend, so I thought I might as well tell mine.
- Give my love to Constance. I will write to you again when I am back in the states.
- — Robert