I have seen pieces of a freshly killed eel move slightly in a pan, and the muscles quiver in the hot grease, but in most instances, these movements are not noticeable unless one is watching for them.
But, why do eels move after death? The movements are caused by muscular contractions, and they may occur at the time of cooking an eel. Eeels have a special type of nervous system which makes it react to heat or other sensations after its death.
It is probably the snake-like form of the eel that causes many people to regard this interesting species with distaste There are a number of different kinds of eels, many of which live in salt water, but much to the disgust of feminine “Isaac Waltons” there are also freshwater eels, some of which may be caught occasionally on hooks.
It is said that when eels are being cooked they will jump about in the frying pan, and I had one enthusiastic person tell me that he once had to tie on the lid of a frying pan to prevent the eel from jumping out onto the floor! This story was certainly an exaggeration unless the man was talking about a live eel.
Related question:
Are eels poisonous? The flesh of eels is, of course, not poisonous, and the creatures do not have a poisonous bite. I have handled a fair number of freshwater eels and have yet to be bitten by one.