Godzilla VS World of Warcraft
Connection:
Both are ancient, highly destructive dragons capable of wiping out all life on a planet (Ghidorah succeeded in destroying all life on Venus and Deathwing nearly destroyed all of Azeroth)
Both their very presence can alter the environment around them
Both caused catastrophic events that would have wiped out all life on the planet if they weren't stopped (Ghidorah caused the Mass Awakening in Godzilla: King of the Monsters and Deathwing caused the Cataclysm in WoW: Cataclysm)
Both act based on what the ones controlling them command them to do (Ghidorah is often controlled by the Xilliens or some other alien race (which isn't always the case) while Deathwing is controlled by the Old Gods and does what they command him to do)
Both are nearly impossible to kill (Ghidorah needs to be defeated by either being overwhelmed by multiple opponents or his enemy gets a power-up that they use to kill him and Deathwing was able to take on the other four Dragon Aspects on his own)
Both have a form of metal on their skin (Ghidorah has traces of gold in his skin and Deathwing has armor made of adamantium)
Both are part of a group of related dragons that appear in their respective series (King Ghidorah is one of three other Ghidorahs introduced in the Godzilla series, Desghidorah and Monster X/Keizer Ghidorah and Deathwing is part of the Black Dragonflight and one of the five Dragon Aspects)
Both are neither from Earth origin (King Ghidorah is an alien and Deathwing is from a different planet similar to Earth)