Lewis Marshall was an animation character design consultant for William Hanna and Joseph Barbera. He began his work for them in the mid 1950s and was credited in the Cinemascope Tom and Jerry cartoons. This was the first time that the human characters regularly showed their faces on screen, with the designs being fairly accurate.
Lewis Marshall continued to work for Hanna-Barbera through the 1960s. For example: He provided design consultant work on The Fantastic Four.
He seems to have been replaced by Iwao Takamoto.
Lewis Marshall was credited in the two remixed Tom and Jerry cartoons by Tom Ray.