Unicorn boy. 1
(Book)

The first few years of Brian Reyes' life were unremarkable. Then, one day, a bump appeared on his head, and it grew... and grew... and grew until it was a full-blown, sparkling, singing unicorn horn. That's absolutely the last thing a shy kid like Brian wants, luckily, Brian has his reassuring pal Avery to keep him grounded as weird occurrences start stacking up, like Brian's breakfast muffin talking to him, or a bizarre black cat offering him a business card. But when shadowy creatures from another realm kidnap Avery, Brian has to embrace his fate to rescue his best friend.