[Bjarni]

Viacom/Nickelodeon acquired the rights to the TMNT franchise, but what does the franchise have?

Steve Murphy and Chris Allan were able to continue using Ninjara in different comics because they apparently owned the rights to the character because they created it. That probably means that she is not a part of the TMNT property.

Which makes me wonder what is a part of the property (character wise)

Ryan Brown created Leatherhead, The Rat King, NoBody, The Mutanimals ect.
He was working with Mirage during the 80's and 2000's cartoon, so it was no problem using these characters (like how they used Usagi), but wouldn't it be a problem now. I'm assuming that Peter Laird didn't get millions of dollars for selling Ryan Brown's characters.

Which brings to question if any of the characters from the guest comics could be used, like Bloodsucker for example. Doesn't Rick Veitch just own that character himself? Since he created said character?

And then there are characters that were created by Peter Laird, but didn't start in the TMNT Universe, like The Fugitoid. His first comic was made back in 1983 and he's Mirage oldest character. Sure, he appeared tons of times in the TMNT stories, but was he sold as well?

The characters I'm certain Viacom must have bought are those that Peter Laird and/or Kevin Eastman created mostly by themselves, like:
The Turtles, Splinter, Shredder, The Utroms, April O'Neil, Casey Jones
Karai, The Foot, Hamato Yoshi, Baxter Stockman, The Old Superheroes,
The Triceratons, Shadow, Cha Ocho,
All Volume 4 characters
Bebop, Rocksteady, Krang, Rock Soldiers, Neutrinos,
The 4Kids characters and Venus

But the question remains;
Does anyone know how far and how much Viacom actually owns of the TMNT universe?