onlooker who gives uninvited comments on some happening, esp a chess game

gambler who hastens to make away with the winnings

pond-side crane

bystander who takes no part in the happening

person on the lookout for benefits/advantages nearby

it is a Chinese two-part allegorical phrase. Literally, a crane near the pond, which will target the food to eat. Nowaday, people tend to use it to describe a spectator or someone who sits on the side and doesn't get involved be it in sports, politics, etc.