Edit
An image sample from Drawcrowd.
Drawcrowd does not work with the bookmarklet and you must manually alter part of the image URL (typically /large/) to /original/. The download and expand buttons on Drawcrowd are deceptive in that the original is usually kept hidden to mitigate bandwidth costs. If the /original/ returns a file not found error, then the /large/ image is accepted as the original.
It is Danbooru policy to either replace samples or delete them. See image sample for more information. See howto:drawcrowd for how to upload images from Drawcrowd correctly.
See also
This tag implicates image_sample (learn more).