Ka-ching is a widely used generic money sound effect rather than a quote tied to one specific character or franchise. It imitates the bell and drawer sound associated with old cash registers, then spread through radio, TV, games, and internet editing as shorthand for profit or spending. Online, creators still use it because the meaning is immediate: money just appeared, changed hands, or became the punchline. It often fills the same quick emphasis role as a ding sound effect in short-form edits and reaction clips.