noun: Someone who is a lookalike, or doppelganger, for another person, but less attractive. While it usually refers to physical appearance, the term is versatile and can, in theory, also be applied to inferior versions of non-human things/animals or used to compare one individual negatively to another in terms unrelated to physical attractiveness.
Spencer Pratt is a beat-up version of Charlie Hunnam.
Charlie Puth sings like a beat-up version of Sam Smith.
Mello Yello is a beat-up version of Mountain Dew.