Born in 1963, Willis was active in the comics field in the late 1980s through the mid 1990s, working as a penciller, inker and colorist for indie and mainstream companies such as DC Comics--for whom he inked an issue of Millennium: The Manhunters in 1988.
His previous works include a number of indie comics whose art duties were handled by then fledgling Insight Studios, of which Willis became an early member under Studio chief Mark Wheatley. With Insight Studios and freelancing, Willis worked on titles such as Blood of Dracula and Vampiric Jihad (1987) for Big Apple Comics, The Black Hood for Impact Comics (1991), Insight's Out of the Vortex (1993) and Doctor Cyborg: The Clone Conspiracy (1996), which he also wrote) and The Adventures of Baron Munchausen for NOW Comics. 1991's Aliens: Genocide was perhaps Willis' most high profile work.
In 1992, Willis also worked on a number of Tarzan comics from Malibu Comics, including scripting and art duties on Tarzan in the Glittering City--an adaptation of the last chapter of Tarzan and the Lion Man--and coloring on the Tarzan the Warrior and Tarzan: The Beckoning miniseries. He later worked on an issue of Leonard Nimoy's Primortals for Big Entertainment Comics in Aug. 1995, an issue of Harpy: Prize of the Overlord in 1996 and Small Press Expo SPX '97 in 1997.
Willis apparently vanished from the comics industry after this point as no additional information can currently be found about his career.
Genocide was the fourth Aliens miniseries and the first to delve entirely away from the characters of the Alien film franchise in its plot. It introduced a number of new ideas to the series, most notably the idea that excretions of Alien Queens can form a powerful new drug.