There’s plenty of new rare mobs to chase down in 11.1, so here’s several ways to find them!
The Map
First off Blizzard shared a handy map for the rare enemies in Undermine. The rares grant reputation in addition to the many individual rewards and are split into three types. There are the regular rare mobs that are entirely soloable, the elites which might require a group (depending on spec/item level), and the Cartel elites, which spawn from local events. The drops also include parts for the 
G-99 Breakneck while the rep you can get is 20/50 for your Renown track from the regular rares/elites, while the Cartel elites grant 150 with the Cartel you selected for the week.
The Addon and Video
Then there’s the classic addon, Handynotes, which has been updated with the rare mob locations. You can also check out this video for more specific locations of the rares.
