This plugin for Daily Global Check tracks which rare mobs have already been killed in Draenor. When a rare mob has been killed, the icon for that specific mob disappears from the map..
The Tanaan Jungle rares are daily and are also part of an achievement, a green skull on the map means that the specific rare has not yet been killed for the achievement, a blue skull means that it has been killed once but not today.
You can choose to track the Jungle Stalker achievement criterias rather than the daily rare vignettes by checking the plugin specific option in the Daily Global Check frame.
This is a plugin and requires Daily Global Check!