Bartosz Sztybor was born in the summer of 1984 in Warsaw, Poland. He is a writer of both comic books and movie scripts, a scriptwriter of TV shows and documentaries, and an author of children's books.

He has written dozens of comic books and graphic novels in Poland, including the series for teens Niezła draka, Drapak! with art by Tomasz Kaczkowski; the award-winning autobiographical graphic novel Come Back to Me Again, with art by Wojciech Stefaniec, and a few works without words illustrated by Piotr Nowacki (Tainted, It's Not About That and Options).

His short comics and strips have been published in almost every comic book magazine and most major newspapers in Poland. He has won many awards for his comics and his movies at various festivals all around the world (including best writer awards in Brazil, Spain and Poland).

His movies have been shown, and his books published, in many other countries. He debuted in the United States in 2010 with a few short comics published in the comics publication Zombie Terror, and in 2016, he published his first story in France, Unlucky, with art by Ivan Shavrin (published in Doggybags vol. 10).

Cullen grew up in rural North Carolina, but now lives in the St. Louis area with his wife Cindy and his son Jackson. His noir/horror comic (and first collaboration with Brian Hurtt), The Damned, was published in 2007 by Oni Press. The follow-up, The Damned: Prodigal Sons, was released in 2008.

In addition to The Sixth Gun, his current projects include Crooked Hills, a middle reader horror prose series from Evileye Books; The Tooth, an original graphic novel from Oni Press; and various work for Marvel and DC. Somewhere along the way, Cullen founded Undaunted Press and edited the critically acclaimed small press horror magazine, Whispers from the Shattered Forum.

All writers must pay their dues, and Cullen has worked various odd jobs, including Alien Autopsy Specialist, Rodeo Clown, Professional Wrestler Manager, and Sasquatch Wrangler. And, yes, he has fought for his life against mountain lions and he did perform on stage as the World's Youngest Hypnotist. Buy him a drink sometime, and he'll tell you all about it.