Roald Dahl used imagery to describe characters in the book, "Matilda". These vivid descriptions help to bring the characters alive and readers can imagine how the characters look like or how they behave.
1) Description of Miss Trunchball
"She had once been a famous athlete, and even now the muscles were still clearly in evidence. You could see them in the bull-neck, in the big shoulders, in the thick arms, in the sinewy wrists and in the powerful legs." (Pg 66)
2) Description of a newt that Lavender finds in her backyard pond