There are several potential causes, depending upon exactly how long after death you are seeing this phenomenon. If the color change was noted immediately after death, I would suspect the stomach tissue was dead prior to the snake's death. Within an hour or so of death, the stomach may turn green from reflux of small intestinal contents including bile back into the stomach. More than a day after the dead of the snake, the green coloration is likely due to bacterial decomposition of the tissue.
death
The final result of a an untreated peptic ulcer or perforated stomach would cause the contents of the stomach would leak into the intestinal cavity and cause acid damage and poisoning to the internal organs resulting in death.
penises
Muscle spasms can cause this.
The green part of the potato can cause stomach upset, and even this can cause death when the animal is distressed. (if it's a pealed potato, then ok).
Heart Attack
Well, 99.9% of the reasons are because youre pregnant. That .1% would be cause the love your stomach cause its soft.
Vicodin cannot cause acid in the stomach because acid is already naturally inside the stomach but the over use of the Vicodin could cause you to get sick so if you have not eaten then you would be throwing up acid from your stomach which could lead you to think that it could cause stomach acid.
Well there is a myth saying that they'll explode. What will really happen is that it would ruin their stomach lining and probably cause death in a matter of weeks or days.
Algae
cat acid
Changing your diet suddenly can cause irregularities in you stomach or intestines