Mandacaru said:
Zombie scorpion-trollkin which use their heads, carried in sacks, as clubs.
Utterly unofficial, but they exist (not spuriously either) in my game
The Scorpion-Walktapus, for no other reason than it has exactly 20 locations.
One of our old GMs had poleaxe-wielding zombie pixies, they were strong (being zombies) so could use a poleaxe and had no negative damage modifier, they were small and so harder to hit, they had no concept of totla hits and, best of all, they were invisible until they attacked. So the first you knew about it was when a poleaxe appeared in front of you and smashed into your abdomen.
I liked the Vampire TigerSon because it had 4xSTR in Tiger Form and scared the willies out of players. The same GM as above looked through the bestiary and saw that Sharkmen had 2.5xSTR in shark form, so he did a Vampire Sharkman that had 5xSTR in shark form, then he sent it against us as we were on a boat in the River of Cradles. As it approached, he gleefully told us what it was, expecting us to cower in fear until we pointed out that running water destroyed vampires and it vanished in a puff of logic.
I like centaurs because they are quick and hard. I also like vampires and especially Gloranthan ones because they can walk around in the daylight.
Even though I personally hate spiders, I like Cragspider, who is one of the best Gloranthan characters, in my opinion.
Trolls are funky as well. But vampires and centaurs are probably my most favourite Glorantha critters, even though neither is particularly Gloranthan.
As for Gloranthan-specific creatures, they all seem to be a bit rare.
Creatures that are different in Glorantha are more interesting. Trolls, of course, are always fun and have a good background. I prefer tolkein-style elves, rather than talking bushes, although talking bushes themselves are perfectly good Aldryami. I've never cared much for dwarves, since they turned against the horses in the Narnia books (Dwarves for dwarves, indeed) and Gloranthan dwarves don't particularly interest me. Ogres are much more fun. Broos can be a laugh when they start messing about. Wind Children are interesting, but not much fun indoors.