1000 hours in ms paint
Usually used for the worst kind of pictures – art that is so incredibly poor-quality that looks like a crude ms_paint drawing. For example, copy-pasted assets, such as heads or other body parts, done in ms_paint quality; bad linework; lack of detail; or disproportionate body parts. Art with this tag is rarely approved on today's standards, and will typically be deleted; in rare cases, though, there can be exceptions – for example, meme.
While the tag has "ms paint" in the name, the picture doesn't have to be made in ms paint. The pictures has to look so bad to the viewer they would say "why this picture is drawn by 10-year-old in MS paint?", either intentionally or not.
The example on the left is with this tag, but the one on the right is without it. You can clearly see the quality differences between both.
Discussion on whether or not to keep the tag is at topic #42566