Just remember this. Most non musicians dont necesserially make the distinction.
The steriotype of an opera singer, with the viking garb, and being fat (for female) only really applies to the operas of Wagner and his ring cycle of operas (also the offical music of Nazi Germany (we stole Beethoven from them))
The majority of opera singer are neither viking, nor fat. So, take that into account, any figure that is singing, will work for an opera singer.