I have a DS7 who is exactly like this. He was afraid of a Winnie-the-Pooh book that my MIL purchased for him. It was one of the newer ones and had owl eyes glowing in the dark. A Babar book freaked him out for weeks. He was afraid to sleep at night. I always screened his books because of this issue, but those two slipped in and caused big problems.
We were visiting family and they asked if he could watch Peter Pan. Ummm... I didn't know what it was like, so I had to go check the "feel" of it. He seemed okay with it, but before long he came out of there and didn't want to watch it. I think it was the "meanness" in Hook's voice and the scowl on his face. LOL
Also, when playing imaginary games (similar to the monkey game that you mentioned), he reaches points where he will request to stop the game; he says that it's "too thrilling" for him. He uses the word "thrilling" to describe the intensity. He knows that it's not real, but it "feels" real to him. I don't know what this is other than a very vivid imagination. It's definitely the visual, real or imagined, that gets my ds.
All of that said, I can definitely see that he's been improving in this area over the past five or six months. I think he's found a way to cope with it or maybe he's just growing out of it some way.
