Onyon is a Tabemon monster that appears in worlds 1 and 2. it has many different forms, such as Native and Gas Mask onyons. the description in the Tabemon Encyclopedia is: It makes people cry at times, but there is always a high demand for it. it is small, white and has two little black legs. it is round and has a jacko-lantern mouth. it is a level 1, and very easy to eat.