Novel variants of clade 2.3.4 highly pathogenic avian influenza ... by Gu, Min; Zhao, Guo; Zhao, Kunkun; Zhong, Lei; Huang, Junqing; Wan, Hongquan; Wang, Xiaoquan; Liu, We / Emerging Infectious Diseases.
Sometimes a dynamic character is called a developing character. Flat Character A character who reveals only one, maybe two, personality traits in a story or novel, and the trait(s) do not change.
Any walk-on that could successfully be made into two-dimensional character should...unless doing so awkwardly upstages an important character/moment or harmfully dilutes the pacing of a scene. A two-dimensional character is the same as one-dimensional character except for the fact that they show one emotion or character trait. They are also known as cardboard characters, your cutouts, because they lack dimension.