Also known as: もぐもぐ, モグモグ, mgmg
The abbreviated romaji form of the onomatopoeia "mogu mogu," or "chew chew."
Normally written もぐもぐ or モグモグ, "mg mg" in romaji is very commonly associated with Ringo (Touhou) in Touhou 15: Legacy Of Lunatic Kingdom, as her official game art displays it when she is shown to be Eating (which is constantly).