^^ B5 and Daffy Duck are both Warner Bros. productions, so they could do that. Trek could have pulled stuff from the Paramount library, but they didn't. I think B5 showed future humans a little more realistically than Trek did with it's uber-evloved humanity nonsense.
I have to knock points off of Babylon 5 though for barrowing so much from Deep Space Nine. Warner Bros. should have tried to be a little more original ... in my opinion.
The first four seasons were good though (unfortunately season 5 was shockingly bad). I liked Crusade, a shame it was cancelled before it aired.