Other than porn, do you guys have an unusual reference source that you use for art?
Like, tools and references that not meant to be used for art purposes?

Recently I'm using a random face generator to practice portraiture.

If porn, do you use the poses for non-sexual art?

It is common for artists to use real pictures of humans or animals to practice drawing, even if in non-sexual artworks. Sometimes, artists also use 3D modelling screenshots as a base to create background scenes or complex character poses. And of course, you have people who use existing artworks to trace over them and create their own "artworks" (this is plagiarism of course).

There are also more controversial methods such as this which ruffled a few feathers to say the least. I recall there being one artwork which was a trace/paint over of a real-life bestiality picture, but I don't remember if it was taken down or not. Additionally, there are also the more distasteful ones which used real-life pictures of suicide, murder victims or tragedy events to draw death/gore artworks with. Not sure if you wanted to know these sorts of "unorthodox" references.