Yeti was larger than a hatchling but still very young. If he is my second choice (my only other found possibility is Atlantic LongArm) he will be 2 months older than he looks since that would make him a small egg species and 30 - 60 day are spent in the water column. In this case, the hatchling is quite distinct and until
Roger Hanlon captured and raised a couple, no one knew what the hatchling became.
Typical and size are not two words easily used with octopuses with a lot of meaning. Even octos from the same brood with the same food supply can vary greatly. That being said, if you will look at the last page of any of my briareus threads you will see a tape measure and the expired octopus (and we encourage others to do the same as it is the only real way we can measure them).
Here is a link to Tatanka and I would say he was a "medium" for the species. We have seen them quite a bit larger (Legs - Capt Fish is one that comes to mind) and a few smaller. Do note that final pictures are not usually at the octos largest size if they survived a complete life cycle. During senescence they stop eating and live off their body so they become smaller, more in girth than length.
To best navigate to find journals about a species, select Advance Search at the top of any page and then type briareus into the search keyword box and select search by Title only. You can also put a member's name in the User Name box to further limit your search but I suggest looking at several (looks like I am up to 11 briareus now
). I encourage members to title their journals with the animal's name and species to make searching easy (and will make this change for any who request it since the titles require a staff member to be changed). Once you pick a journal you can right click and open in new page/tab to retain the list. On the octopus' journal, click Last and, in most cases, final pictures will be near the end of the last page.