There was an NPR story one time about how a poisonous toad that had been introduced to an area was causing mass mortality events for crocodiles and other predators.

The solution was to take out the poison from toads, inject them with a compound that makes the crocodiles nauseous, and then set them up as bait for the crocodiles. The crocodiles then learned not to eat the toads.

Of course, any sort of attempt with a similar method should be cleared with your local government. It's not something that some vigilantes should be trying to handle alone without the proper guidance, safety, and approvals in place.

https://www.npr.org/2024/08/16/g-s1-17159/cane-toads-freshwater-crocodiles-australia-invasive-intervention