While the oldest image I have is the pre-Creek Craig and Tweek image from 2006 that I just posted earlier, the oldest Tweek image I have is dated August 17, 2012.

Literally 13 years ago today!!! (What an odd coincidence I decided to do this today of all days!)

Reverse imaging searching did not return an artist at all and none of the “similar” things Google through up look remotely in the same style.

Artist: Undetermined

Please drop a response in the replies if you know the artist.