I am a Unicorn! by Michaela Schuett -- "While Frog is convinced he's a unicorn with his clip-on tail, party hat horn, and ability to fly on swings, Goat is determined to show Frog that he's not, but Goat is about to learn that when someone truly believes, sometimes magic happens."
Kevin the Unicorn: It's Not All Rainbows by Jessica von Innerebner -- https://zipadeeyoga.blogspot.com/2020/03/zipadeebee-well.html
Not Quite Narwhal by Jessie Sima
Thelma the Unicorn by Aaron Blabey
Unicorn Day by Diana Murray -- Every one welcome, even a horse with a pretend horn!
A Unicorn Named Sparkle by Amy Young -- "A picture book about a little girl who desparately wants a beautiful unicorn as a pet, but winds up with a less than desirable one instead"-- Provided by publisher.
Unicorn Thinks He's Pretty Great by Bob Shea
Unicorn Yoga by Gina Cascone and Bryony Williams Sheppard
You Don't Want a Unicorn by Ame Dyckman