Uplifted dogs I can handle. Makes a sort of sense. There's a story just finished in 2000AD that features uplifted dog warriors defending the last of humanity (if they are actually still in existence) in Antarctica from what seems to be uplifted insects. Thought it would be corny at first, but it turned out ok.
My impression of Vargr was actually formed in the pilot of Andromeda. The Nightsiders are so obviously Vargr inspired, but I didn't know Traveller then. An actor with elongated snout/nose, and lots of hair, dressed as a New Romantic. Sounds about right.
The biggest problem with Vargr has been the artwork. It really is just dog heads stuck on human bodies. That is soooo wack. Apart from the fact that it just looks damn silly, how do Vargr talk? Their jaws are too big. Vargr should resemble dogs just as much as humans resemble chimpanzees. In 99% of Traveller artwork, Vargr are just plain old dogs on their hind legs wearing trousers. Blame the artists.
As for Aslan, I ignore the lion comparison. I treat it a lazy classification by the intial human contacteers. I was into Star Frontiers in my youth, so I look to Yazirians for inspiration. Ok, lion-monkeys, but with more going on. In MTU Aslan have no relationship to big cats whatsoever.
Hivers are starfish? Maybe that was the initial inspiration, but they certainly don't resemble any starfish I've met. Only similarity is 5 or 6 pseudolimbs. And they're are cool. More like Niven's Puppeteers than starfish.
Have there been any decent aliens in rpgs? (Sorry, don't know 2300, don't want to know, don't like the basic premise).
Dralasites, another Star Frontiers type, were pretty good. Though somewhat like dwarves, perhaps - tough, slow, like jokes.
There was a Spacemaster 2ed alien that didn't have any eyes, just sensors on the foreheads. Can't remember what they're called.
Aliens in literature don't fair much better. Vernor Vinge's honky tonk spiders were always a bit silly, in my book. Even Iain M Bank's aliens are often just a good excuse for fart jokes, though I thought the Voehn warrior race (vacuum capable) and those tumbleweed-form intelligence agents were pretty cool in the Algebraist.
Niven/Pournelle's semi-sentient Grendel's are pretty good too.
It's a thin field, though.