User blog comment:TheMaximumMatt/Question: If you could have the Loud House crossover with any show ever, what would it be?/@comment-31541999-20171109175715/@comment-32173189-20171109221617

@ Billybug

Back when Supergirl still aired on CBS (before it moved to the CW) it had a crossover episode with The Flash that aired on the CW. Granted the reason they were able to pull it off was probably due to fact that both properties were owned by DC Comics.