Just learned something interesting. Doug as he originally appeared is in the Public Domain. Both, the USA Network ident & Florida Grapefruit advert featuring Doug were released without copyright notices & not registered within 5 years, making them PD under 80s-era copyright law.*
*This only applies to these appearances & not the later Nick and Disney Series and movie, which are copyrighted by Nick (Owns the rights to the original episodes only) and Disney ( Owns the later series and characters).