* Age: Charlie is a young man, likely in his late teens or early twenties, as he's fighting in World War I.
* Slim and Agile: He's described as a good runner and climber, suggesting a lean and athletic build. This is crucial to his character as it highlights his adaptability and resilience.
* Innocent and Youthful: Charlie's naivety and lack of experience in the real world are emphasized throughout the novel. This might imply a boyish appearance, even as he matures through the horrors of war.
* Brave and Strong: Despite his youth and innocence, Charlie displays immense courage in the face of unimaginable hardships. This suggests a spirit that transcends his physical appearance.
It's important to note that the novel focuses more on Charlie's inner journey and emotional struggles than his physical attributes. His physical appearance is likely to vary based on each reader's interpretation and imagination.