In most action movies, or any movie that is formulaic in nature, there are several stereotypical roles. One of these is "funny fat guy who dies." You know them. You've seen them. Wayne Knight, in Jurassic Park? The old man, Hamish's dad, in Braveheart? The list could go on.
Most of the time, it's a guy, but sometimes it's a woman. Such as Aida Turturro, in Deep Blue Sea.
Although, I must point out, Deep Blue Sea does break every other convention, by having the last two people alive be "Funny Black Man" and "Convict with the Heart," and for killing "Repentant Female Scientist who Strips."