Brian P. Cleary is an American humorist, poet, and author. He is best known for his books written for grade-school children that explore grammar, math and poetry in humorous ways. In his role in the digital division of American Greetings, he's put words in the mouths of Dolly Parton, Christina Aguilera, William Shatner, Meghan Trainor and more. The multi-million selling author has performed poetry workshops in 500 elementary schools across the county. He lives in Cleveland, Ohio.

Brian Gable is the illustrator of many of the best-selling Words Are CATegorical® books, as well as the Math Is CATegorical® series. Mr. Gable lives in Toronto, Canada.