In the book Holes by Louis Sachar, X-Ray’s real name is Rex.
X-Ray is one of the main characters and is known for his ability to find valuable items in the dirt. The nickname ‘X-Ray’ comes from his knack for digging up treasures and the way he seems to see through the ground. His character plays an important role in the dynamics of the group at the juvenile detention camp where the story takes place, and his real name, Rex, highlights his more personal identity beyond just his nickname.