This is by far the most bizarre title for a children's space book I have found. In it facts about space travel are shared in the form of an imaginary voyage through the solar system. The odd title comes from the anticipated living conditions on the various planets (i.e. the crocodiles may exist on Venus because of its dense atmosphere). So unless you have seen this book you wouldn't know it was about spaceflight.
Wilkins, H. Percy. Illustrated by Jauss, Anne Marie. Clouds, Rings and Crocodiles: By Spaceship Round the Planets. Boston: Little Brown and Co. (148 p.) 22 cm. Cloth, DJ / London : Harrap. (127 p.) 20 cm. UK 1955, US 1956
The spaceship designs are similar to the Bonestell rockets but have their own unique interpretation.
The space station design is also very different from the popular ring-shaped ones.
Landing and exploring the moon are the real focus of the text. Unfortunately they don't actually show you any crocodiles living on other planets.
But it does have this wonderful image of looking down on Saturn from Mimas.