King of the Zoo written by Erica S. Perl, illustrated by Jackie Urbanovic is a delightful zoo book. Carlos, a chameleon, thinks he's the king of the zoo, but sees signs for all the other animals saying they are King of the Zoo and Carlos comes unglued!
The art is done in pencil and watercolors and is bright and friendly. I love how Carlos changes colors like the fur pattern of the different animals. This could lead to some interesting discussion on camouflage, science tie-in.
Carlos keeps saying, "The king of the Zoo is ME, that's who," so that refrain could be used by the students as a chant to participate in the storytelling. I'd use this with preschoolers to second graders.
It would go with a theme Storytime on zoo, chameleons, or kings and queens, if you stretch it some.