I understand that Smeagol was a Hobbit-like creature at least and always thought the "river-folk" were distantly related beings (similar to say, the Hyena and the Dog, but not actually exactly the same species. Many people seem to believe the contrary and talk as if the "river-folk" were, in fact, Hobbits for sure.
The Tolkien Gateway, Wikia, and others even specify he was originally a stoorish hobbit, where does the evidence to support this come from - or is there any?
The thing relevant quote from The Hobbit:
Riddles were all [Gollum] could think of. Asking them, and sometimes guessing them, had been the only game he had ever played with other funny creatures sitting in their holes in the long, long ago, before the goblins came, and he was cut off from his friends far under under the mountains.
Gollum brought up memories of ages and ages and ages before, when he lived with his grandmother in a hole in a bank by a river (…) Gollum remembered thieving from nests long ago, and sitting under the river bank teaching his grandmother, teaching his grandmother to suck—"Eggses!" he hissed.
While the idea of the hole, enjoying riddles, and living a seeming idyllic life are reminiscent of Hobbits, they do not generally like water so would not be boatmen or live along a river bank, and thieving eggs for food doesn't sound very hobbitish either.
Of course there are exceptions to the rules of Hobbit society (Bilbo, being one of them) and things evolve and change over-time, perhaps an ancient predecessor society such as that something more than 500 years old (such as Gollum) may have been more of a fishing kind of creature (I believe it was a group of Brandybucks that did enjoy living nearer the river in "modern" Hobbit culture), but I just don't remember anything that said for certain he was in fact a hobbit for sure - let alone specified any stoorish origins. I'd love to know where this idea originates.
I know there are other passages in LOTR's such as the one where he talks about even forgetting what bread tastes like and it has been years since I've read the entire thing so I hope I am not missing something obvious here.
Is there anything more definite or is this just a hinted at thing left up for personal interpretation that most people have interpreted to mean it is a sure thing that he was once a hobbit?