A few different nebulae have picked up the nickname "Butterfly Nebula", but NGC 6302 has a particularly good claim to that title. But coleopterists are advised to keep their distance, as the central star of this nebula is unimaginably hot.
Thanks to our old friend pareidolia, this nebula does a particularly striking impersonation of a butterfly, especially because that brown bar of dust at the center looks like the insect's main body. In fact, it's behind that dense collection of dust that the nebula's central star is found. That star is one of the hottest ever discovered, with an estimated temperature of more than 200,000 Kelvin. That suggests that the original star that birthed this nebula was absolutely gargantuan.
You can see a more complete version of the image on the left - click on it to expand. It was taken by the Hubble Space Telescope soon after its upgrade back in 2009. It captures in striking detail the bright ionized gas that makes up most of the nebula, along with the brown dust torus that surrounds the central star and bisects the rest of the nebula, helping to create the butterfly illusion. The star itself is invisible in optical wavelengths, but it can be seen burning brightly in the ultraviolet spectrum.