Favorite children's picture books (with horses)

I have a weakness for children's picture books with horse-related themes. For example, Blackie, the Horse that Stood Still is a discovered-as-an-adult favorite, as are Wild Horse Winter, Snow Ponies and Fritz and the Beautiful Horses. (C. W. Anderson's illustrations make his books an absolute given to make my list, of course.)

There was also a black & white, or maybe black & white & sepia-toned, series featuring a young colt who was constantly getting into trouble in the barnyard -- pulling the billy goat's beard, waking up the rooster, etc. The titles were something like "X and the Morning" and "X and the Wood Duck."

Anyone have any particular favorites new or old to recommend?

That series you mentioned might be the Flip series illustrated by Wesley Dennis. I think they were all titled "Flip and the {something}".

Thank you, thank you! I couldn't find them in whatever box they'd disappeared in during the last move.

I absolutely love Susan Jeffers's illustrations in Robin McKinley's adaptation of Black Beauty. The Girl Who Loved Wild Horses is another favorite. Marguerite Henry's The Album of Horses, Steven Kellogg's Best Friends, Jill Krementz's A Very Young Rider should be on every horse crazy girl's shelf. Fritz and the Beautiful Horses, Where Have the Unicorns Gone?, I Rode the Red Horse, the Billy and Blaze series, the Flip series, Ride like the Wind, and Leonardo's Horse are all more than decent as well.