Drawings Referencing Famous Artwork - Paying Homage to Art Masterpieces

When you bring the worlds of historic art and familiar and lovable characters together the result is sure to be a masterpiece in its own right. Artwork that puts a spin on the work of famous artists of yesteryear can either bring a new level of intensity to the piece or even inject a bit of humor. There have been many pixiv posts featuring this kind of art.

Of the examples below, how many of the original artworks can you name?