Simon is described by Golding as one of the in-between boys; a "skinny, vivid little boy" with straight black hair. His bright eyes make Ralph think he is always happy and wicked, which is not true. Simon shares the experiences of both the littluns and the older boys. He has innocent perceptions and feelings like a littlun, but has extensive knowledge, just like the biguns.

Simon shies away from any confrontations. He is uncomfortable speaking at the assemblies and only does so when talking directly to Piggy. He doesn't want to get laughed at or made fun of. The only times he is scared is when he feels that there is going to be an argument. When he senses tension between Jack and Ralph, the fear shows in his face, but he is too scared to do anything about it. Jack picks on Piggy for not getting wood...