I like frogs, real and origamic. The photo of this one in the book looked really great, so I thought I’d try it. It uses lots of box-pleating to get the long, thin legs, and does interesting things to get the flippers. Plus you get a nice froggy-shaped plump body. Cool.
This piece is published in Origami Dream World (ISBN 978-4255002385) by Toshikazu Kawasaki. The book is out of print, but often available used at a reasonable price.