From a popular song by Pearl Bailey in the early 1950's.
A dishonest, shady person, or scam artist who has found his mate, who complements each other's undesireable behaviour.
Don't blame him only for cheating the old woman out of her money, his wife helped. It takes two to tango.
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.