Crossover

A Daria fanfic or fan art that mixes canon Daria elements (characters, settings, plots, etc.) with those from another fictional work entirely, permitting interaction between those elements. The non-Daria work might be a story, novel, movie, computer game, or other media, such as the Marvel Universe, the Simpsons TV show, or the movie Seven Days.

For a variation on this concept, see Dariaverse crossover.