Yagher began building monsters when he was growing up in Dayton, Ohio. At 19, he was running his own Halloween-mask business and after a year at Ohio State University he relocated to California to pursue a career in special makeup effects. His break came when he was hired as an assistant on The Last Starfighter. He honed his skills on such shows as Cocoon, Michael Jacksons Thriller, and Friday the 13th, Part IV, before being offered his first job as head of makeup special effects on Nightmare on Elm Street, Part 2
Since then, Yaghers creations and effects have graced the screen in such films as Face/Off, Starship Troopers, Volcano, The Hidden, The Fan, Conspiracy Theory, and Honey I Blew Up the Kid. Other theatrical credits include all three Childs Play films, Nightmare on Elm Street, Parts 3 and 5, Radio Flyer, The Seventh Sign, and Glory, among others.
Yaghers directing credits include several episodes of HBOs Tales From the Crypt, for which he recieved a Cable ACE nomination. He also directed all of the shows wraparounds and promotional spots, one of which earned him an Emmy Award in 1992.