- "Yes, Kopa was my creation all the way. If I remember correctly, the language is Swahili. I had spent some time in Kenya and still had my words and phrase dictionary."
- —Simmons about Kopa
According to his website, Simmons spent his early artistic career as an actor performing in everything from children's theater to extra work in films such as Falling In Love and The Muppets Take Manhattan. He played Judas Iscariot in Jesus Christ Superstar and a sadistic killer in Titus Andronicus.
Later, Simmons became a professional writer, spanning from magazine interviews and articles to video games and documentaries. He even wrote children's novels and comic books. Simmons also wrote original stories for three Disney movie novelizations, one being The Lion King: Six New Adventures, published by Grolier. In this novel series, Simmons wrote the first book and introduced the lion cub character, Kopa, who is the son of Simba and Nala.
To this day, Simmons travels globally, sharing his knowledge and experience as a teaching artist and guest speaker, and conducting creative writing workshops for young children. Currently, Simmons is the founder of the annual Kids Comic Con and the Color of Comics Exhibition.