Godzilla

Godzilla (ゴジラ Gojira) is a mysterious creature similar to King Kong. Apparently, it is big, green, snorts fire, and is lizard-like.

Fiction

Super-spy agency S.H.I.E.L.D. had encountered Godzilla before. Alerted to trouble in Oregon by Dum Dum, S.H.I.E.L.D. employee Nicholas threatened to quit if it was "that big green, fire-snortin' lizard" again. Prisoner of War!

These stories do not fit into the normal Marvel continuity. See Earthforce for details.

When Superion was running amok in upper New York State under the influence of one of Bombshell's cerebro-shells, reporter Irwin Spoon compared him to Godzilla when the Autobots he encountered told him the Aerialbot combiner was actually one of the "good guys".

Prowl had absolutely no idea what Irwin was referring to. Inside Story!

While guarding Fearswoop, Jolt read a Godzilla comic book. Rising Storm #3

Godzilla had his own Marvel Comics series in which he was hunted down by Dum Dum.
Given Spoon's statements about movies, it might be the case that, in-universe, the Japanese made a movie about Godzilla's real-life monster rampages—after all the Marvel continuity contains both superheroes and superhero comics—but drawing firm relationships between the Marvelverse, the main US continuity and the Earthforce continuity is problematic at best. Earth-120185, anyone?
Super-God Masterforce head writer Masumi Kaneda has stated that God Ginrai (ゴッドジンライ) was named so that omitting every other Japanese syllable yields the word Gojira (ゴジラ), the original Japanese name for Godzilla.
There is another Japanese monster movie, Hojoni, as shown in "Kremzeek!"
Around the time Jolt was seen reading a Godzilla comic, IDW Publishing began putting out their own Godzilla series. Coincidence, or product placement?
Grimlock's alternate form in Robots in Disguise is likely a reference to Godzilla, with the shape of his head, claws, and overall size, he also bears a striking resemblance to the 2014 movie version of Godzilla. Reference, or blatant cash-in?
Additionally, he has been seen using several moves from the Godzilla films in the franchise, most notably his gravity defying kick from Godzilla VS Megalon.