After studying electronics and working in a variety of short-term jobs, including as a guitarist, Grant travelled throughout Europe to improve his painting style.
He worked in various styles, ranging from cute children's artwork to dark and realistic adult images.
Grant has produced illustrations for many books, including the Fighting Fantasy gamebooks FF 3: Deathtrap Dungeon, FF9: Shamutanti Hills, FF 11: Khare Cityport of Traps, and FF13: The Seven Serpents, Terry Pratchett's Where's My Cow?, The Demonata series by Darren Shan and the Bartimaeus Sequence (USA) by Jonathan Stroud.
He designed the album covers for Iron Maiden's Fear of the Dark, Virtual XI, Death on the Road, The Final Frontier and From Fear to Eternity, as well as the single "The Reincarnation of Benjamin Breeg", making him the only artist other than Derek Riggs and Mark Wilkinson to have been used to draw Eddie on more than one Iron Maiden album.
Grant designed a number of covers for video games, including Baal and Captain Fizz Meets the Blaster-Trons.