Frank Brunner studied at the New York University Film School and at the School of Visual Arts in New York City. He has worked as a magazine illustrator since the late 1960s (Win Magazine, I'll Be Damned). Around the same time, he did his first comics for Creepy magazine of Warren Publications.
For Castle of Frankenstein, he also did a comics feature, called 'Smash Gordon'. He eventually got a job at Marvel, starting out as an inker on 'Tales of the Watcher' in 1969. He did several other jobs for Marvel, like 'Howard the Duck' stories with Steve Gerber, until he got a regular run on 'Dr Strange' with Steve Englehart in 1973.
During the 1970s, Brunner was also a productive illustrator of paperback covers. He eventually focused on animation design (like on the 'X-Men' cartoon series) and fine art painting during the 1980s. As a cover artist, he was hired by Star Reach Productions and DC Comics. He additionally drew for Star-Reach titles like 'Star-Reach' and 'Quack'. In the 1980s, he appeared in Marvel's Epic Illustrated.
He did graphic albums like 'Voyages' (Dragon's Teeth Productions) and 'Thieves' World Graphics' (Donning Publishing), and appeared in Eclipse titles like 'Alien Worlds'. In the mid-1980s, he was the artist of First Comics' title 'Warp'.