When Rufus Butler Seder’s Gallop!hit the scene back in 2007—featuring Seder’s Scanimation technology, which makes the animals on each page of the book appear to move when the pages are turned—readers responded. Gallop! landed at the top of bestseller lists and stores had trouble keeping it in stock. That book was followed in 2008 by a sports-themed sequel, Swing!, and Workman has just released a third book, Waddle!, as well as a Spanish-language edition of Gallop! for the U.S. market called ¡Al Galope!

Like Gallop!, Waddle! focuses on the movements of several animals—a penguin waddles excitedly on the cover, and a frog, pig, elephant and bear are among the creatures found inside. Unlike its predecessors, Waddle! lets readers see these animals in color, instead of black and white. “The addition of spot color seemed like a natural part of the evolution of Rufus’s work,” says Raquel Jaramillo, children’s book director at Workman and Seder’s editor. “It’s a subtle enhancement. The key to Rufus’s Scanimations is that the movements are based on real animals and people—they’re not cartoons or animated drawings. And color in nature is nuanced. So once Rufus decided to use color in his work, it was important to him that it be done artfully.”

At Blue Willow Bookshop in Houston, Tex., owner Valerie Koehler says that sales of Waddle! have been “very nice” so far and that the book is on display along with its two predecessors. Koehler says the addition of color makes the new book even more attractive to customers. “It’s a great little gift, a great price. It appeals to a wide variety of people.” Gallop! was a strong seller for the store when it was first published, Swing! less so, though Koehler notes, “I don’t think it has to do so much with [the sports] subject matter as much as we had done such a good job with the first one.”

In September, Workman released ¡Al Galope!, a Spanish-language edition of Gallop! for the U.S. market. It shares its title with a version of Gallop! that was previously released in Spain, but that’s where the similarities end. “¡Al Galope! in Spain is a kind of riddle book—lots more text,” says Jaramillo. “Our Spanish-language edition is a translation of the original.” (Jaramillo, who is bilingual, did the translation herself.)

The editor cites another Workman title that the company translated into Spanish—What to Expect When You’re Expecting—as evidence of the market for ¡Al Galope! “Since we can assume the people who bought Que Puedes Esperar Cuando Estas Esperando have had babies, it’s a safe bet that there are a whole bunch of Spanish-speaking toddlers out there who will want ¡Al Galope!” she says. “There are also a lot of English-speaking parents who want to teach their young children how to speak Spanish, and ¡Al Galope!, with its simple rhythmic text and motion verbs, is the perfect introduction to the language.”

All four Scanimation titles are being promoted on a newly launched Web site for the series, which includes information about the books, the technology they implement and a matching game for kids. There are currently 3.3 million copies of Gallop! and Swing! in print; Waddle! will add 400,000 copies to that tally.

Waddle! by Rufus Butler Seder. Workman, $12.95 ISBN 978-0-7611-5112-8

¡Al Galope! by Rufus Butler Seder. Workman, $12.95 ISBN 978-0-7611-5415-0