When a turkey has gone bad and no longer safe to eat the turkey will usually become slimy in feeling and the turkey will also give off a rotten smell.
The rotten smell of a bad turkey will smell like sulfur or a rotten egg smell.
Bad rotten turkey will also cause the color of the turkey to fade or darken and usually you can really notice the rancid smell of the bad turkey which will usually take your breath away or make you vomit when you smell it.
Raw turkey can have a slight odor until cooked but bad turkey will have a rancid smell that may make you vomit.