An acronym meaning "3D pig, disgusting," the last two words a reference to a video of a Korean ranting about how awful America and its
people are.
It refers to real-life
human women, for their tendency to have functioning bodies with un-oiled skin, small eyes, imperfect fat distribution, skin that sags
due to realistic amounts of collagen, 12 pairs of ribs, and small breasts, as opposed to 2D drawings in Manga,
Anime, and Western cartoons, which emphasize expressive eyes and ideal bodies.
It's usually used in the subject of porn, mostly in sarcasm.