Not really dubious. Captain N was created by Nintendo Power's own team member(who is also a regular Nintendo employee), and Nintendo America literally took control of the character. The only rights DiC has is distribution of the show. There's been absolutely nothing to point out anything that contradicts that Nintendo still owns it. I mean, he's called Captain Nintendo. No way they wouldn't hold onto the rights. The only way they aren't going to is if they never use the character again, but since the show is still being distributed via DVD's, they need to keep the copyright up because of its connections.
"The character Captain N first appeared in
Nintendo Power magazine, created by a
Nintendo staff member and magazine editor named Randy Studdard (who presented Nintendo with a formal proposal that included the character as a company spokes-character, the origin and premise, and the Saturday morning cartoon as part of the entire marketing campaign). The original concept involved Captain N (originally known as "Captain Nintendo") as a Nintendo employee and the
Mother Brain as piece of programming from a Nintendo game pak (that was infused in an explosion with experimental "organic" ROMs) that went rogue. Captain N had the power to temporarily give life to characters and items from Nintendo games. The story left a door open for a sequel (Mother Brain is temporarily defeated but her return was said to be inevitable, and Captain N vows to stop her when the time comes).
Nintendo of America, Inc. later decided to follow Studdard's ideas and create a cartoon series, opting neither to credit nor to compensate its creator.
DIC Entertainment was shopped as the animation studio, and changed various aspects of the original idea while keeping the main premise of the Captain opposing Mother Brain as he interacted with a number of video game characters.
[1]"
The only other Captain N thing was a comics published by Valiant Comics, but is part of the Nintendo Comics set.
There's also; The closing credits on the series itself say "Copyright 19XX By Nintendo of America, Inc." DiC is not mentioned. This is the last part I'm having trouble confirming at this time.