Cane toad
The first cane toads were brought into Queensland by Reginald Mungomery, an entomologist. Before 1935, Australia had no toads. The entire continent, full of various frog species, had no toads. Tough and always moving into new areas, the cane toads started reproducing and expanding outwards every wet season. This "invasion front" moved around 10 km a year until the 1960s, when it began speeding up significantly.