The meaning of dreams
I think the pig in your dream may represent someone you hate in your life.
You think he is stupid and lazy, and you want to fix him.
Cutting off his head means that he wants to eliminate his influence on you. His head represents his thoughts and may be offensive to you.
The pig desperately wants to find his own body, which shows that he wants to combine stupid thoughts with actions.
You think the pig's barking and movements are terrible, because in reality this person may have a violent and extroverted personality.
However, sometimes dreaming of killing other animals or other people often reflects an ideological struggle to eliminate their own shortcomings.