The UK has six “mosaic” Hawkers and 2 “browns”. Along with these eight, I’ve included the Blue Emperor/Emperor Dragonfly (Anax imperator) because I have had one instance of it being confused.

To see them all together, side by side, both male and female, see my comparison (un-annotated because it would get cluttered):

There are also a few more specific hawker comparisons and details available: