That new business is a real feathered oof-bird for the owners.
feathered oof-bird
idiomAny large, plentiful source or supplier of money.
Origin
disputed originUK late 19th century–1920s.
The company turned into a feathered oof-bird after they signed that massive government contract.
Investors flocked to the startup, hoping it would prove to be a feathered oof-bird that could sustain their portfolios for years.