Teddy Brewster is a fictional character from the play "Arsenic and Old Lace," written by Joseph Kesselring. He is portrayed as a charming but delusional man who believes he is Theodore Roosevelt, the 26th President of the United States. Teddy is known for his energetic personality and his habit of digging locks for the Panama Canal in the basement of his aunts' home. In the play, Teddy's antics provide comic relief, as he interacts with his family and other characters. His delusions lead to humorous situations, highlighting themes of mental illness and the complexities of family dynamics. Teddy's character adds depth to the story while emphasizing the importance of love and acceptance.