As an actor, he has been seen in such films as The Mask, Steel, Congo, Tim Burton’s Planet of the Apes remake, and the 2003 vampire vs. werewolf film, Underworld.
Underworld was Grevioux’s first produced writing credit. He came up with the original concept/premise and wrote the original screenplay along with director Len Wiseman, launching the Underworld franchise. He appears in the film himself as a lycan, Raze, and returned as the character in the Underworld prequel Underworld: Rise of the Lycans, which he will also be adapting into a comic book mini-series. He has also expressed an interest in telling more Underworld stories in comic form if this proves successful.
Using Romeo and Juliet as an archetype, Grevioux based Underworld on his experiences with interracial dating and the tension that it often causes. He also brought a scientific element to the world of vampires and werewolves by basing vampirism and lycanthropy on a viral mutagen rather than the mysticism typically associated with these two mythic creatures.
Early 2006 saw Grevioux form two comic book imprints, Astounding Comics Studios and Darkstorm Comics Studios. Grevioux’s Astounding Studios imprint was to focus on all-ages titles such as Valkyries, Guardian Heroes and The Hammer Kid. The Darkstorm Studios imprint was a more mature line, including the books Alivs Rex, Skull and Guns and Uzan, The Mighty.
Grevioux’s voice is distinctively deep. In the commentary track of Underworld, he relates that during the promotion and launch of the film, many fans asked him if his voice had been altered by computer, and were surprised to learn that it had not been.
Grevioux wrote Marvel Comics’ New Warriors volume 4. Grevioux also wrote Adam: Legend of the Blue Marvel, a character he created years ago as a young teenage comic book fan. The mini series was drawn by Mat Broome and Roberto Castro.
He sold the original screenplay for the film adaptation of his Darkstorm Studios graphic novel, I, Frankenstein, to Lakeshore Entertainment, which also produced the Underworld films. The story follows the original monster of Victor Frankenstein who is the only force that stands between the human race and an uprising of supernatural creatures determined to overthrow the world.