Been listening to the audiobook this week, it's really neat, actually.
Mark's introduction with the wolf pack has this really cool moment where he almost gets too close to comfort with the Alpha, and this seems to foreshadow/mirror his interaction with post-nuke Godzilla on the submarine's deck.
Ghidorah apparently requires a massive dose of radiation in order to regenerate his head, which he obtains from Rodan's volcano - this wasn't clear for me from the movie alone, but it cast the post-credit scene and the question of the body parts staying dead into a whole new light.
All the expended stuff about the Titans is really interesting. The Skull Island outpost is - obviously - number 33 and during the undesignated Titan's (Kraken) awakening there's namedrops to both Lagos Island and someone called Devlin.
There seem to be a couple more F-words than I remember, too. Does the movie has the part where Mark talks about the first time they tested the ORCA prototype on a pack of whales? Is it mentioned/shown in Aftershock by any chance?
goblin shark (plural goblin sharks) [ˈgɒblɪn shärk'], noun:
1. a shark with a long pointed obstruction from forehead and growing to 3.8 meters in length; Mitsukurina owstoni.
2. not a reference to Guiron.