Someone who raises money for a particular place, event, or cause. The phrase alludes to collecting money in a can. Oh, the kids are out being can-shakers for their softball team today.
can-shaker
n. a fund-raiser. (As if a person were holding a can for the solicitation of coins from passersby.) Fred was a professional can-shaker for a museum. Maybe he has some ideas as to how we can raise some money.