The Thing (1982)

In John Carpenter's remake of the 1951 classic horror film:

• the repellent autopsy scene, in which Norris (Charles Hallahan), a member of an Antarctica research team experiencing sub-zero temperatures and extreme paranoia, had a heart attack -- and as a doctor attempted to revive his heart with resuscitation paddles, his stomach became a fanged, gaping maw that bit off the doctor's forearms; also, the 'spider head' separated from the body, sprouted spider legs and scurried away
• the shocking scenes of the 'blood test' used by R. J. MacReady (Kurt Russell) and Windows (Thomas Waites) to 'smoke out' the alien creature as the participants sat tied together and had their thumbs sliced open - with the blood sample from Palmer (David Clennon) indicating that he was infected - and his incineration by MacReady
• the scene of discovering that Blair (Wilford Brimley), slowly going insane, had escaped the storage shed by tunneling under the ice