The legendaries are super rare, and you can only get a chance once every minute, which makes it hard/impossible to farm for.
Every 60 seconds if you are doing overworld/shard content there is a hidden roll. If you hit on it then the next overworld/shard mob you kill will have the drop. So as long as you are killing something at least once per minute, you are getting the chance to get it.
The drop chance of overworld legendaries and shard legendaries is the same.
These items have a very low chance to drop from overworld enemies and unshared dungeons (anything that isn't a shard or a raid).
|Cat Ears||Transmog (Head)|
|Angel Wings||Transmog (Shoulders)|
|Demon Wings||Transmog (Shoulders)|
|Elongata Pet||Pet (crated)|
These items have a very low chance to drop from any enemy in shard dungeons.
|Demon Horns||Transmog (Head)|
|Dragonfly Wings||Transmog (Shoulders)|
|Squirrel Tail||Transmog (Shoulders)|
|Alley Cat||Pet (crated)|