I can say this was one of my favorite book from middle school.
This book color catches the readers attention because it has many colors and it seems to involve animals and a lot of people like animals and the title leaves people to question what is it about and what may happen.      
Common characteristics-  The last three has the same author and their covers all have this odd focal point a words whether its bolded out different color or in the middle of all the words that are squeezed together.  However, the first 2 book covers seem to be a documentary about important time and person in history.  For the last 3 book covers there is consistence within the book because the way the book cover is set up.  Furthermore, I really like books so i have no comment.