In Australia, where the cane toad is a horrible pest (and bad for kitties) they recommend putting the cane toad in a plastic bag in the freezer, which I duly did. Sadly the cane toad apparently lived at least long enough to hop around a fair bit as I find him, in his freezer bag, wedged down the front of the drawers ......... Not nice. Mind you it is nicer than the treatment my nephew gave to a mouse that the cat was playing with. I asked him to rescue the mouse, thinking we could put it outside, but no, what does he do but catch the mouse and throw it in the open fire - he never did that again, I can tell you. I shrieked at him for over an hour.
Poor lad is now wanted by the police in three states - seems the old saying that people who are cruel to animals are also likely to be nasty to others has a lot going for it.