by angilas » Wed Dec 18, 2013 10:22 pm
They can't sue over Zilla if it wasnt named Godzilla anymore than they could sue over gorgo.
Toho wants to protect their IP and that means barring any dilution to the Godzilla trademark by creatures that are extremely similar such as have the same roar (well GINO's roar was close but weird). According to one court case Godzilla is interpeted as an nuclear dinosaur that has always been living in the modern era and breaths fire. GINO was an iguana and while his hurricane breath resulted in fire much less so than the nuclear breath of Godzilla. Now Baragon might also fit that definition if it werent Toho's property but we cant say for certain Baragon is a dinosaur. Gamera aint, and he might even be able to get away with parody, at least at one time were the plots the same and the turtle replaced with a dinosaur.
Long story short I think you'd have to replicate the roar, use the zilla name, or have a strikingly similar gigantic fire breathing dinosaur related monster before Toho would for infringing their Godzilla trademark. If you rehash their prior film plots in a serious manner theyd probably also sue for copyright infringement.
I dont think there are any other kinds of IP they can sue you on Godzilla for in the US unless say you choose to sell an object in a Godzilla shaped package- trade dress infringement.
Toho KK owns a number of Japanese patents such as high speed film techniques which are still active but other than barring you from filing an identical thing in the states I'd imagine you could still practice their patented technology without a patent suit.
And unless you work for toho or a subsidiary and steal some info you're sworn never to reveal such as a suitmation technique and use it in your films they can't get you for trade secret infringement either. So that leaves Trademark and Copyright to worry about.