>>150747159
Well, in terms of "official" crossovers, a lot of /co/ media is/was highly episodic, so stuff from the 70s like Scooby Doo crossing over with literally anyone and everyone is easy to look over and doesn't really interfere with anything.
As far as "unofficial" crossovers, putting /co/ characters in anime outfits is really funny, and quite a few Western cartoonists have taken inspiration from Japanese media and/or worked with Eastern animation studios (plenty of BTAS episodes were animated by Japanese studios, and this is true of many other cartoons as well, even today) so there is some familiarity and in some cases a bit of blending of styles between east and west (not to mention that liking western cartoons and liking anime are considered similarly nerdy and gay and the communities have a decent bit of overlap)