Buns is the generic term that can be used to mean any type of bun, though it's commonly used to mean the standard buns that Mystique Sonia grows to feed First Squad. Mystique Sonia grows her buns by watering the seeds with her special saliva. Before Egret Queen & Ox King joined Big Green, she had to feed everyone because Woo the Wise was a horrible cook. And apparently afterwards, Mighty Ray grew to dislike them, which really makes her upset and angry as seen in "Porcupine Castle".
Hurricane Lee also grows buns. Though never shown in all episodes, he hugely abhors Mystique Sonia's cooking (and Mystique Sonia herself), and would prefer only his own buns. His buns don't appear to have magical powers, but when in combat (as seen in Turtle Cannon Competition), he throws them as ammunition instead of using his axes.