He worked briefly at Walt Disney Studios before joining Metro-Goldwyn-Mayer in the early 1940s. His first work at Metro-Goldwyn-Mayer was for Hugh Harman and Rudolph Ising. After Harman and Ising left, Lah worked briefly on Bill Hanna and Joseph Barbera"s Tom and Jerry series.
He then joined Tex Avery"s unit as lead animator, where he remained until the studio closed in 1957.
During Avery"s absence in 1950-1951, and after Avery left Metro-Goldwyn-Mayer in 1953, Lah was given co-directorial cr on many animated shorts. After he left Metro-Goldwyn-Mayer, he briefly rejoined Hanna-Barbera at their television cartoon studio as an animator, then joined Quartet Films, a commercial animation studio that created television commercials for Kelloggs and Green Giant Foods.
Lah died on October 13, 1995, in Los Angeles, California.
He is best known for his work at Metro-Goldwyn-Mayer studios, primarily as a member of Tex Avery"s animation unit He was an active member of ASIFA-Hollywood, serving on the board for several years.