Five of these rares are tamable by hunters, and The Razza is highly sought after by BM specced hunters because of his beautiful unique blue and white armored coloration. The Razza also has his own post on this blog where I have a little more information on him and some more screen shots for anyone interested. The other four tamable rares in the zone are not unique.
These rares do not share spawn timers, and their spawn times all seem pretty similar and range probably somewhere between 1-2+ hours. Like other low level rares they give a ton of experience for those leveling in the area.
Also I'd like to note that as far as I know, Diamond Head cannot currently be reached by characters that don't have a flying mount. He spawns in a pond at the top of the eastern plateau of the Twin Colossals. The only way up there for characters around his level post-cata would be through a summon or riding on the back of a friend's 2-seater flying mount.
Again, as promised here is a map showing where each of these rares spawns and/or patrols. ~
|Click map to enlarge|