カモネギ

Also written かもねぎ, 鴨ネギ, 鴨葱, 鴨ねぎ

Meanings

Expression along comes a sucker just begging to be parted from his money See also: 鴨が葱を背負って来る (かもがねぎをしょってくる).
double stroke of good luck; perfect timing!; how convenient (for you to show up)!