Originator
Originator (in Japanese, 本家 honke) is a tag used to define origin or the birthplace of an extremely popular series in the media, usually in anime, manga, or doujin. To put it simply, one illustration that started up all the craze and the rage.
Usually these illustrations are popular, that generated lots of views and marks given by various users throughout.
The alternative usage to "originator" would be "Birthplace".
Usage at pixiv / How to identify an "originator"
Usually tags that are labelled as 本家, 元祖 (ganso) or 本人 (honnin, lit. "Original person") are the famous illustrations found not just at pixiv, but also other magazines, CD cover, or video sharing websites (Youtube, NicoNicoDouga). One of the best example would be Black★Rock Shooter, which pixiv was the origin birthplace of this craze.
Japanese defined "Originator" as:-
1. Tags that depicts well known illustrations that started a craze that everyone follows. One illustration that started it all. An illustration that spawned, started, or triggered various parodies or meme also works the same way. Many illustrations that are found in famous PV of Vocaloid songs fall into this category.
2. Established famous artists or mangaka that submits their illustrations on pixiv also falls under this category. Sometimes they will also use tags like ”プロの犯行” (puro no hankou, lit. "Professional's offense") or "本人" to identify such illustrations.
*Related illustrations