Danny Williams is Megan's rambunctious, redheaded 8-year-old brother. He is fond of jokes, although never with the intention of hurting anyone. He sometimes feuds with his younger sister Molly, but always sticks up for her and Megan in the crunch. He can be reckless, and does not hesitate to take charge when a desperate situation gets worse.
He first came to Ponyland when the ponies needed Megan's help to defeat The Smooze.
He was voiced by Scott Menville, best known for the voice of Robin from Teen Titans and Teen Titans Go!.
In the My Little Pony Annual 2013 comic story "The Fall of Sunset Shimmer", Danny's name (and also Megan and Molly's) appeared in a flier for the Canterlot High Sundance. He's apparently a teacher who, along with Megan and Molly, handles submissions for the Yearbook in Room E.