Muller was born in the Bronx, New York, the son of Mildred and Romeo Earl Muller. He was raised on Long Island. His talents in the arts were evident very early on. At age 11, he became a puppeteer at his grade school and eventually he began writing his own plays. His career in theatre began when he joined an acting troupe called "Theater Go Round" in Virginia Beach, Virginia with producer/friend Lesley Savage. At this time Romeo wrote plays such as Angel With The Big, Big Ears and The Great Getaway, which eventually became the Rankin-Bassoff Broadway play A Month Of Sundays. Since Muller was a big man at 6'2", 300 pounds, he decided to stay away from acting and turn his attention towards writing.
Career
After writing material for comedian Jack Benny, Muller was discovered by CBS founder William S. Paley and selected to be a staff writer for the prestigious Studio One and Philco Theatre. He wrote one of the most popular episodes for the Studio One series entitled "Love Me To Pieces, Baby". In 1963, Muller met with producer/directors Arthur Rankin, Jr. and Jules Bass and began a relationship that would last for years. Rankin and Bass asked Romeo to write a screenplay for their first Network television special, entitled Return to Oz, which aired on NBC's the General Electric Fantasy Hour. The special was a success and set the stage for the most popular holiday television special of all time Rudolph the Red-Nosed Reindeer. Muller embellished the short story into an hour-long broadcast and added a variety of characters into the story. He is also known for his screenplays in other such films as Santa Claus Is Comin' to Town, The Little Drummer Boy, Here Comes Peter Cottontail, and Frosty the Snowman, among many others. In 1965, several Theatre-Five radio productions featured Muller as writer and/or actor. He was also the voice of the narrator, a talking sun in the first three Strawberry Shortcake TV specials from the 1980s, which he also wrote and co-produced. Muller read his favorite and first Christmas story every year on Christmas Eve on New York radio station WGHQ. This story was reworked with a different ending for an animated film in 1992 and aired days before Muller died. In 2002 the book Jill Chill & the Baron of Glacier Mountain by Ed McCray featured a character named Romeo after Muller. The book is written in the style of the old Christmas specials that Muller had written.
Death
Muller died of a heart attack in his sleep on Wednesday, 30 December 1992, shortly after receiving a diagnosis of cancer.
