.The
Crab Nebula (M1) is the remnant of a supernova that was first observed by Chinese astronomers in 1054. William Parsons (Lord Rosse) drew what he saw through his 36-inch telescope, and thought it looked like a crab. This is how the nebula got its name. It's in the constellation Taurus, not Cancer the Crab.
Personally, given that drawing, I'd have named it the Pineapple Nebula. What about you? People are more familiar with the
Hubble Space Telescope image of the nebula.