Slow painful death for the poor crayfish. The crayfish seems Kinda big for the puffer, ghost shrimp or small snails would probably be a better option. One bite and they would be gone, much quicker death.
Ugh. Just reading that is was a slow death turned me off from going to watch - thanks for the heads up. I used to have a Chinese Water Dragon that I fed crickets & pinkies to. I couldn't do the pinkies these days. At least the crickets went instantly.