“You’re not the first one who’s had trouble with money,” said Mr. Roberts, scrutinizing Mr. Weasley closely. “I had two try and pay me with great gold coins the size of hubcaps ten minutes ago." -- Mr. Roberts (GF7)
Mr. Roberts is a Muggle man who worked as the campsite manager for the 1994 Quidditch World Cup.
Mr. Roberts is very curious. He was interested in money transactions at the Quidditch Word Cup, wondering why many were having trouble with paying. He asked Arthur Weasley if he was foreign. He also thought it was odd that so many campers pre-booked their spots on the campsite (GF7).
His curiosity meant he needed to be Obliviated a lot, which gave him a "strange, dazed look." He said "Merry Christmas" to Harry and the others as they left the campsite (GF7).
Mr. Roberts and his family were subject to humiliation and minimal torture from the Death Eaters at the Quidditch World Cup. His family was levitated above the group of Death Eaters, one of them flipping Mrs. Roberts upside down so that her nightdress fell down. They also spun the youngest Muggle child "like a top, sixty feet above the ground" (GF7).
Mr. Roberts had a wife and two children, and they lived in a stone cottage at the front of the campground.
A very curious Muggle.