Why did they forget the sulfur?
 

In the comics and the 2003 show, Triceratons breathe a mixture of nitrogen and sulfur with no implied presence of oxygen, with the 2003 show straight up stating that oxygen is the element that poisons Zog. However in this show they only state nitrogen as a necessary element for breathing, with no acknowledgement of sulfur or oxygen. The problem however is that earth's atmosphere is primarily nitrogen anyway, which makes the claim that he isn't getting it somewhat puzzling. Now we can assume it's still the oxygen that poisons him or the lack of sulfur, but it's a weird detail to leave out.