12 books • 3 series
Carl Writes a Letter (Carl Can)
Carl Enters a Contest (Carl Can)
Carl Makes a Plan (Carl Can)
Carl Goes on a Field Trip (Carl Can)
Katie Helps Out (Katie Can)
Katie Gets a Pet (Katie Can)
Katie Meets Carl (Katie Can)
Katie Is a Big Sister (Katie Can)
How to Be Friends with This Merman (How to Be Friends)
How to Be Friends with This Unicorn (How to Be Friends)
How to Be Friends with This Werewolf (How to Be Friends)
How to Be Friends with This Gnome (How to Be Friends)