Red King vs. Zilla
Location: Rocky Mountains
Setting: Deciding to seek out his greatest challenge yet. Red King goes across the world seeking for Godzilla, King of the Monsters to take his title only to instead due to his dimwitted brain to encounter and mistake Zilla for Godzilla due to his resemblance.
Be an interesting match. Reptile Brute vs. Swift Reptile. Strength vs. Speed. Reliant on strength vs. Reliant on intellect.
Added in 3 days 1 hour 27 minutes 43 seconds:
Anguirus (Showa) vs. Rodan (Heisei)
Location: Monster Island
Setting: As both of Godzilla's most trustworthy allies and friends. To see which one is more in position for being second-in-command, Godzilla issues an friendly yet rough challenge between Anguirus and Rodan.
Won't be surprised if this match had already been done.
Added in 2 days 19 hours 41 minutes 6 seconds:
Kumonga (Showa) vs. Spider Uros
Location : Congo Basin
Setting: No premise needed other then just being a fight between two spider based kaijus, could also be seen as kind of a reference or nod to the J'ba Fofi as well, a cryptid said to be giant spiders that inhabits the Congo Basin.