The third of nine children, Gregory Warmack was born into a poor family on Chicago’s West Side in 1948. He credits his mother’s love and support during difficult times and her recognition at an early age that he was “artistic.” In church (where he sang in her gospel choir) he first made pictures (especially of angels) that he gave to anyone who needed hope. He drew and painted on cardboard from cut-up boxes. By his teens he was also collecting rocks, beads, trinkets and other found objects and making jewelry from them to sell on the street. He carved bits of bark and wood into faces that resembled African masks. When kids gathered as he made art on his back porch, he shared inspiration and his meager art materials with them. At the same time, to help support his family over a period of 15 years, he held a succession of “day jobs”—newspaper carrier, waiter, busboy, dish washer, cook, hairdresser, salesman, window-display designer, record-store clerk, masonry repairman and furniture upholsterer.

In 1978 at age 30, his life changed. Mugged while selling jewelry on the street, he was shot twice in the stomach at point-blank range. During emergency surgery and a six-week coma in the hospital, Warmack had a transformative "out of body" experience. Regaining consciousness but at first unable to talk or scarcely walk, he recovered slowly over a period of months.

When able, he resumed his art. Not long after, he discovered a new medium: discarded amber chunks of an industrial byproduct he called "sandstone," which he could easily carve as reliefs and sculptures, many with Egyptian and African themes. Gaining a reputation in the neighborhood, he soon began to call himself Mr. Imagination (Mr. I, for short) and sought greater recognition. Despite the setback of an apartment fire in 1982 that destroyed much of his work, Mr. I captured the interest of a local art dealer—Carl Hammer offered him his first one-man show in 1983. Mr. I would continue to show there, as well as in a dozen other museum and gallery exhibitions in New York, Philadelphia, Boston, San Francisco, Seattle, Dallas and elsewhere.\

Locally, his new status led to invitations to conduct workshops for children. Meanwhile he continued to sell small pieces on the street and in bars, working as always with found objects. In 1988 he discovered bottle caps and the jewel-like flash and texture they afford. He started by making a flamboyant bottle cap coat, hat, staff and mask to wear to a party, and soon added bottle caps to a chair, a large picture frame, a velvet-cushioned throne, and more. In 1999 his life-size, bottle cap encrusted cow for Chicago's public art "Cow Parade" presaged his later bottle cap mule for Bethlehem, PA's "Miles of Mules" in 2003.

His work attained national and international recognition (see resume) with exhibitions. He also reaffirmed his commitment to children and community with a series of outdoor embedded concrete sculptures (or "grottos," as he calls them). The first was in a children's community center on Chicago's South Side; others (domes, benches, arches, walls) were in Milwaukee, Orlando (for the House of Blues), Winston-Salem, and Bethlehem, PA (the Millennial Arch at Lehigh University and later the LANTA "Grotto" bus shelter at the Banana Factory.

In 2002 he left Chicago to relocate in Bethlehem, to find more peace and green in his life. In addition to work in Pennsylvania, he has continued to travel widely for commissions and shows (see resume).

A second, devastating fire in January of 2008 destroyed Mr. Imagination's home, killed his beloved dog and charred much of the work he had stored there. Like a phoenix rising from the ashes, however, he has been laboring to salvage what he can and to create new work in his current north Bethlehem location. He is currently in the process of planning a move to the Atlanta area.