Adiraiju

Just a heads-up: some of these facts were previously established in the comments of Dr. Miller's journal entries (and the big infodump in the middle was copy/pasted), but I want to just put them out there for clarity:

-The "Plan Z" Rocket from 1965 was actually created over the course of five years of construction, and was intended to be the first rocket to send an entire crew to establish a permanent base on the Moon. Using it to send Gamera off to outer space was basically a spur-of-the-moment idea. The nose cone was originally intended to hold several years of supplies, and the rocket was to be deconstructed to build the base itself. A second rocket was built over the course of two years, and launched in 1967 to establish the UN Moonbase. 

-Earth has gotten a terrifying reputation in the rest of the galaxy, and is often seen as only slightly below Nebula M78 on the interstellar list of "Do not mess with this place, the locals will END you."

-Every dragon in the Universe is the spawn of King Ghidorah, if he is driven off of a planet, he leaves behind a slew of dragons of various sizes and abilities to destroy as much life as possible. Upon the death of all life on the planet, the last dragon - the victor - will become a weaker Ghidoran, capable of moving on to destroy other worlds. Death Ghidorah and Grand Ghidorah are a few of these Ghidorans. Monster X was actually a dragon, and upon the destruction of the last Xilians in 2004, the beast evolved into Keizer Ghidorah. He can also control dragons within a few thousand miles, and controlled Manda during the 1999 Battle of Mt. Fuji. Manda was stopped by Baragon and Varan working together.

-The Mysterians originally dwelt in the asteroid belt after the destruction of Mysteroid, but were forced out in 1962 by the arrival of the Kilaaks from beyond the Solar System.

-Pellucidar's fate is still completely unknown.

-The routine and inevitable loss of various "Lost Worlds" shortly after their rediscovery by western science has been acknowledged by dozens of scientists as a strange phenomenon, which has never been satisfactorily explained. The creation of Jurassic Park was an attempt by John Hammond to recreate one of these strange worlds. Despite all the expense, Hammond DID originally plan to populate Jurassic Park with creatures cloned from tissue samples of surviving dinosaurs. For this, the Unknown Island ecosystem seemed like the perfect place to recreate, as the surviving tissue samples from that area are the most complete and well-preserved known today.... However, only four "prehistoric" species are known to have lived on the island during its final years, so this would limit potential expansion for the park's future. Moreover,  when the dinosaurs of the lost islands went extinct, so did the hordes of microorganisms that were needed to keep them alive - plus, a certain amount of genetic manipulation would be needed to reconstruct the decades-old DNA found in the remains. Henceforth, Hammond was left with the problem of it being almost impossible to accurately recreate the lost ecosystem. The animals had been photographed and studied enough so that any change in their appearance or behavior would be noticeable. When Dr. Wu reported that the park could get more species - and even rarer "prehistoric" species, which could be genetically manipulated with impunity while being advertised as the real thing - for a far lower cost with the use of amber-preserved insects, Hammond jumped on the idea and clung to it until the park became a reality. They didn't use monsters or kaiju in the creation of any of Jurassic Park's critters, since - despite Hammond's famous line of "We spared no expense" - Ingen was actually pretty tight-fisted when it came to paying for things that weren't immediately obvious (Such as originally hiring two guys to program and prep ALL of the security features for a rather large island). While it would be possible to recreate the creatures from Vapour Island and Unknown Island, it would be difficult for the scientists of Jurassic World (because recreating the animals without being allowed to use their usual modus operandi of patching holes with various cheap bits of "junk" DNA would be really difficult - and they'd run the risk of being called out for it much more than they already are) and even more difficult for a private party of scientists, even with the Jurassic Park Institute's aid. 

-The 2001 return of Gojira (The first Godzilla, that attacked in 1954) was repulsed by Baragon and Mothra - and Orochi, returned from the stars to influence humanity for good by possessing the body of King Ghidorah, and resurrecting him from beneath Mt. Fuji. Upon the end of the fight, Gojira blasted King Ghidorah into low Earth orbit, whereupon he crashed into Antarctica, burying him in the ice. 

-The Selenites originally used geothermal energy from within the moon to power their civilization. When that was used up, and the moon's core cooled, they switched to solar energy. They were still using Geothermal energy when the Atlanteans landed on the moon, and the two societies never met.

-Dr. Archibald Mitchell's boosted age and health was attained - unbeknownst to him - by drinking some special tea brewed by the Akkala people of Maple White Land. The tea contained a small amount of powdered Blood Orchid blossom. Dr. Miller himself believes it to be due partly to radiation exposure. 

-I'm considering making an "Ask Dr. Miller" series of posts. Would any of you be interested in something like that?