In my humble opinion the most famous race from the Flash Gordon stories is without a doubt the Hawk-men of Mongo. Mostly because of Brian Blessed's fantastic performance in the 80's movie the very second you mention Flash Gordon then someone will inevitably shout "GORDON'S ALIVE!" in a booming voice.
When considering them to make an appreance on the gaming table visually they have remained similar in all the different previous incarnations (shown below from left to right, the Alex Raymond comic, the Buster Crabbe serial)
Similarly their leader Vultan has undergone little change (shown below from left to right, the Alex Raymond comic, the Buster Crabbe serial, the 1980's Filmation cartoon and, of course, Brian Blessed in the 1980 movie.)
So then, quite a distinctive style and one I wasn't sure at first how I was going to get some in 15mm. I had previously discovered the following images on Alan Saunder's excellent 15mm Flash Gordon HOTT army page...
And also this second image from a post on the Rat Trap Productions Pulp forum...
As you can see, these would have been prefect. They were manufactured by M. J. Miniatures who sadly had ceased trading but thanks to the comments on the forum post I realised that the rights to them are now owned by The Scene Miniatures but they were not on their website. Not being the shy type I quickly fired an email through and the owner Mike got back to me pretty much straight away. So I can announce (with his permission of course) that he's having a bit of work done on the Hawkmen mini's and they will be re-released on the 1st May !
This is awesome news as they are perfectly suited to 15mm Hawkmen, I'm prolly going to do a bit of work on one of them to be Vultan but the rank and file will be good to go once painted up.