A few things:
*English grammar botches. General punctuation is missing, and things could be proofread a bit better.
*Invalid creature types. I'm all for creating new types, but a Pteranodon is a Lizard, Moth is an Insect, and so forth. I'm not complaining about Mutant Dinosaur, because I honestly can't tell you what Dinosaurs are supposed to be. They're all Lizards, but I feel like there's more than that.
*When referring to a Legendary creature in its card text, you only need to state the name, not the full card name.
*Instead of "Island Basic Lands," you should say "Basic Islands."
*Landfall is not exclusive to just Mountains and Forests. If you want it to be just Mountains and Forests, remove Landfall and just say "Whenever a Mountain or Forest enters the battlefield under your control."
*You don't have to say "tap" for costs anymore. Just say "{r}{r}{g}, {t}:"
*Put lines between your paragraphs.
*Colons between costs and effects.
*In regards to Anguirus and Ghidorah, blocking additional creatures is nice, but it's a good way to die early.
*Anguirus's stats, colors, and abilities are spot-on for the character.
*Ebirah's first ability can be rewritten as "Opponent's creatures lose Islandwalk."
*Ebirah may also be a bit overcosted, perhaps?
*Ebirah is a good blue fatty, perfect for the color.
*Godzilla's regenerate cost is nice, but its Landfall effect is kinda wonky. Out of the three, I'd probably go for the counter, but trample would work better overall.
*"King Ghidorah gets +2/+0 if a creature entered the battlefield or was exiled this turn."
*I think Ghidorah's overcosted. Ideally, this is a card that'd do a lot, but with its blocking effect essentially meaning death and its morbid-esque effect being nearly useless without a good sac engine, you're essentially paying 8 for a 6/6 flyer. 8 for an 8/6 vigilant flyer might work, but...
*Mothra's effects are spot on for its character.
*Rodan is definitely overcost. Perhaps make it a 5 drop or make its double strike static.
*Go Go Godzilla!