I think when they became The Little Rascals.
No, I think the “Little Rascals” moniker started when Monogram Pictures decided to re-release the Hal Roach shorts to theaters in the early-1950s. Roach had sold the “Our Gang” name to MGM, and thus they couldn’t be distributed as such anymore. Then, they went into television syndication probably some time in the mid-to-late-1950s, still using the “Rascals” name. Although, the later MGM shorts (1938-44) eventually made it to tv too, and of course, kept that “Our Gang” name.