In the story, the narrator remembers events from his childhood concerning the birth, short life, and death of his younger brother. "Doodle" was the nickname for his little brother, who was born, weak and disabled, when the narrator was six years old. The child's given name was William Armstrong. The narrator says that giving the baby that name "was like tying a big tail on a small kite." The narrator explains in the story how his little brother got the nickname "Doodle":
Crawling backward made him look like a doodlebug, so I began to call him Doodle, and in time even Mama and Daddy thought it was a better name than William Armstrong.
The narrator's relationship with Doodle, from the time of Doodle's birth until his tragic death, is the focus of the story.
In this excellent short story by James Hurst, Doodle is the younger brother of the narrator of this tale, referred to only as brother. Doodle, from birth, was very different, due to his poor health and his appearance, and this of course is capitalised by his comparison to the scarlet ibis that is found in the tree of the family and the way that Doodle feels a strange attachment to this exotic bird so far from its home. Note how Doodle is described at birth:
Doodle was just about the craziest brother a boy ever had... He was born when I was six and was, from the outset, a disappointment. He seemed all head, with a tiny body which was red and shrivelled like an old man's.
In spite of this unpromising beginning, Doodle does eventually learn how to walk, thanks to the untiring labour of his brother, but it is clear that he will never be able to do the "normal" things that children of his age are able to do, and it is this realisation that partly results in his death at the end of the tale.