To express alacrity in preying on someone, verbally or physically: "He was on that boy like white on rice."

To express a large quantity: "They have more [insert commodity here] than Carter's has pills."

The latter expression hails from the southern side of the Mason-Dixon Line, I think. It's a reference to a now defunct product known as Carter's Little Liver Pills, still on the market when I moved to Atlanta in 1963 but not much later than that.