Old Gregg is one of the most widely known of The Mighty Boosh characters, achieving cult status, a somewhat remarkable feat for a one-off character. This is due in part to a truncated version of his appearance in the "The Legend of Old Gregg" (series 2) being uploaded to Youtube in the form of a clip named simply "Old Gregg".
Old Gregg's anatomy and species classification is a topic of debate. Some say he's half man half fish, others say it's more of a 70/30 split. What is certain is that he possesses strange seaweed-like hair, webbed fingers and green/scaly skin. He has the ability to walk upright, but at times reverts to a frog-like crouch. This alludes to the splicing of Homosapien's and aquatic dweller DNA, or possibly a mutation of the former. This is further supported by Gregg's genitals, which are almost certainly hermaphroditic, more commonly referred to as his "mangina". This strange organ(s) emit a blinding light that apparently possess neurally disruptive qualities, as it sends Howard Moon into a state of unconsciousness.
Little is known about Gregg's early life, with few clues as to his origin. It can be speculated that he had an at least partially normal upbringing, due to his admission that he received an A+ in the secondary school course of Home Economics, for baking a crumble.
Regardless of these earlier years, Gregg eventually ended up inhabiting a deep cavern beneath the Black Lake. His isolation and subsequent loneliness seems to have led to psychotic and homicidal behavior, evident in the horror stories that the fisherman of Black Lake hold true. Three documented cases of a person encountering Old Gregg exist:
- The Case of Curly (aka Carly) Jefferson: Little is known about this altercation except the outcome, in which Jefferson was mounted like a fish trophy and hung on Gregg's cave wall.
- The Case of Mr Hopkins: Unlike Jefferson, Mr Hopkins managed to escape Old Gregg's clutches, but not without serious mental trauma that sends him into panic attacks upon the mention of his assailant's name.
- The Case of Howard Moon: While fishing alone on the Black Lake, during the full moon (Gregg's most active time period), Moon's boat was boarded by Gregg, who proceeded to intimidate him before subduing his victim with his/her/its mangina light-source. When Moon awoke in Gregg's abode, he attempted to leave without causing any ill-feeling, but was soon exasperated by Gregg's poorly conceived attempts at seduction. When Moon insulted Gregg, he was shown the Jefferson trophy, and quickly "changed" his mind about Gregg, claiming he was playing hard to get. The two then broke into spontaneous song, singing "Love Games" together. Later, over dinner, Gregg shows Howard "The Funk", before proposing. Howard reluctantly accepts in order to ascertain The Funk, but is then rescued by his companions, thus successfully escaping Gregg, who is later seen standing on top of Howard's van in a wedding dress.
Old Gregg resides in an sub-aquatic cave that is known as Gregg's Place. The cave contains a cocktail bar stocked with creamy Bailey's, as well as small-scale disco lights.
Gregg enjoys doing water-colours, with self portraiture and the alcoholic drink Bailey's being a common theme. His portfolio includes:
- Old Gregg I: This piece depicts Gregg in seated position, sporting what appears to be a penis, or perhaps just the leg of the chair he is sitting on.
- Old Gregg II: This piece shows Gregg in a less erotic, more whimsical pose, with one hand on the forehead.
- Old Gregg III: This piece is a self-portrait, showing just the facial region.
- Baileys: A depiction of a Bailey's bottle.
- Baileys, but a bit bigger: A depiction of Bailey's bottle, slightly larger than its predecessor.
- As Close As You Can Get to Bailey's Without Your Eyes Getting Wet: A piece of beige paper.
- Old Gregg returned in series 3, in a deleted scene from the episode "Party". In this scene, Howard is shown leading what he believes to be an attractive, young, jazz-loving woman to his bedroom, but after he goes into the room, the 'woman' turns to the camera and removes his/her human face, revealing Old Gregg underneath. He announces that he is "Going to give (Howard) the time of his life" before adding "I'm Old Gregg!" and proceeding into the bedroom.
- Old Gregg appears at the end of the Mighty Boosh Live Tour, emerging from a giant present delivered to Howard. At the end of the show Howard invites Old Gregg into his wheelbarrow.