Bantam Classics is the classics line of Bantam Books, a New York paperback house that began in 1945. Its founders were Walter B. Pitkin Jr., Sidney B. Kramer and the married pair Ian and Betty Ballantine, and the money came from Grosset & Dunlap and the Curtis Publishing Company. Bantam changed hands several times over the decades. Bertelsmann bought the Bantam Doubleday Dell group in 1986, acquired Random House in 1998, and a year later Bantam and Dell were merged into a single Bantam Dell imprint. Today the books sit inside Random House, part of Penguin Random House, and trade listings for the Kafka title still carry the credit "Bantam Dell | Bantam Classics".
As the name says, the line is given over to established literary works, printed as cheap, pocket-sized editions. The Kafka paperback measures about 4 by 7 inches and is priced at $7.99 in the United States, which tells you the point of the line: a book you can carry in a coat and replace without fuss. Penguin Random House's library marketing page also points it at high school and AP or IB readers, so expect a classroom-ready text rather than a collector's object.
On WebToTell the Bantam Classics title is The Metamorphosis by Franz Kafka, in the English translation by Stanley Corngold. It runs to 224 pages, and the publisher lists it as on sale from February 1972. The story begins with the traveling salesman Gregor Samsa waking to find himself changed into a huge insect. It is a short book.
For readers who want more around the text, Random House issues the same Corngold translation in its Modern Library Classics line, with a new introduction by Corngold and six critical essays by writers including Philip Roth, W. H. Auden and Walter Benjamin. The Bantam edition is the plainer route. If you liked the novella and want it in your pocket, it does the job; if you want to argue with it afterwards, the Modern Library volume gives you more to argue with.