Someone or something that is prolific is fruitful or highly productive. A prolific songwriter can churn out five hit tunes before breakfast.
A prolific writer cranks out two novels a year, and a prolific rabbit has baby bunnies every few months. The word comes from combining the medieval Latin prolificus (“offspring”) with a form of facere (“to make or do”). It can also connote something taking root and growing, like prolific poison ivy that takes over the yard.