User blog comment:BannedLagiacrus/Monster Hunter (Movie) Discussion/@comment-6050823-20161128041913/@comment-25083735-20161129001825

According to the game lore, extra menu videos, and merchandise even, rathalos and rathian are both 70 feet long (At Average length, not max, at max rathalos is 80 feet long estimate). If you think any of the monsters are over sized thats becuase the game is kind of an optical allusion, as its 3rd person. This works with heights. viewing someone from 15 feet in the air looks like a small gap, but when you are 15 feet in the air it looks alot higher than it should be.

Basically its just a change in perspective that gives it the allusion of size change. Infact if you convert the CM length and width of any MH monster, for instance, Great Jaggi, to feet, or meters. you would be suprised. FYI according to the game Great Jaggi is actually 42 feet long at max and 27 feet long at minumum. If you dont believe me you can check for your self or do the math.

Considering a rathalos's wingspan is slightly bigger than its length, as well as the plane (which is probably a boeing 787 judging from the short nose and large tail fins), wich has a wingspan of about 190 feet, and it is carrying a partially destroyed wing, also consider the fact the width of the plane also connects to the plane body itself, the wing it is holding is about 60 feet of metal.

The rathalos in the photo is about 2x as wide as the wing, meaning its wing span is about 120 feet, which is absolutely huge. I did notice though that the rathalos in the picture is different from the normal MH rathalos, probably a 3rd gen rathalos.

the rathalos is probably just really big and hollywooditized.

TL:DR the rathalos is supersized.