Take Your Octopus to School Day by Audrey Vernick
Illustrated by Diana Schoenbrun
Sam is a competitive kid who never seems to "win" theme days at school learns a few things about his cephalopod buddy, Thurgood, and makes a new human friend, too, when he sets aside his competitive streak.
My cephalopod- and camouflage-obsessed Mr. 5 went wild for the reveal behind Thurgood's "disappearance," as well as the collaborative multimedia presentation Sam creates with new friend Caleb. I loved the sneaky sprinkling of facts about octopuses hidden in the pages, e.g., the teacher quietly changing "Take Your Octopus to School Day" to "Take Your Cephalopod to School Day" on the chalkboard in order to include Hank the squid. This one is loads of fun for kids who are into random animal trivia, and it would be a great way to dispel first-day-of-school jitters, too.