Answer: invasive species
Explanation: When you introduce a new animal into a system that it wasn't in before, you run the risk of that species becoming invasive.
That is when it starts to dominate. Once the organism starts to dominate,it starts to have all the other species in that food chain crumble. Once the food chain in that area starts to collapse it causes the whole environment to destroy itself. Soon the environment's animals are all gone causing the plant growth to explode.