Tipper (noun)

1. A person who gives a tip, especially to a waiter or taxi driver.
2. A person who gives a small amount of money as a gift or gratuity, usually in addition to the required payment.

Origin:

From tip ("to give a small amount of money as a gift or gratuity") + -er.

Examples:

1. He was a generous tipper at restaurants.
2. She was a good tipper at the hair salon.
3. The taxi driver was pleased to receive a generous tipper.
4. The tipper gave the bellboy a few dollars for carrying the luggage.
5. The tipper left a few coins as a tip for the coffee shop staff.