fly-by-night

fly-by-night (2)  {n.},  {informal}
1. A company that sells many cheap things for a big profit and then disappears.
A dependable company honors its guarantees, but a fly-by-night only wants your money.
2. A person who does not pay his bills, but sneaks away (as at night.)
Hotels are bothered by fly-by-nights.
Categories: bother informal noun