Sniffles and the Bookworm

Sniffles and the Bookworm is a 1939 Warner Bros. Merrie Melodies cartoon directed by Chuck Jones. The short was released as early as November 26, 1939, and stars Sniffles the mouse.
This is the third cartoon with Sniffles, although the plot is more in line with the "books come to life" entries from around this period.

Plot

Mother Goose characters come to life late at night in a bookshop, serenading Sniffles the mouse, and his bookworm friend with the swing song "Mutiny in the Nursery" by Johnny Mercer and Harry Warren, until the Frankenstein monster intrudes.