Bent Fish?

[Corleone]

You're doing it wrong. Put him back in the tank, put the water in the freezer until it's freezing. Actually turning into ice. Just putting ice cubes in, you're only reducing the temperature a little bit, and it's happening slowly. By leaving it sit, it's getting warmer and approaching room temperature. You probably didn't have the temperature any lower than 50F, which is quite cold to the touch, but not enough to accomplish euthanasia.

It has to be literally icy cold - 32F/0C, not just figuratively icy cold to the touch.

 

[WILDER]

That method always worked for me.
Do you have any cloves oil.
I don't like these method hitting on the head, or chopping the head off.