Cane toads in Australia: https://en.wikipedia.org/wiki/Cane_toads_in_Australia

> In June 1935, 102 cane toads were imported to Gordonvale from Hawaii

> Since their release, toads have rapidly multiplied in population and now number over 200 million (...) but also no evidence indicates that they have affected the cane beetles for which they were introduced to prey upon.