So, let's start with the starters.
9: The moon moth is apparently a pun for Greninja, also known as Gekkouga (It's 'moonlight' and 'moth', and each word can write '月光 (げっこう, Gekkou)' and '蛾 (ガ, Ga)' in japanese.) As we know this is one of the starters, it's taken as a reference to typing, making this a Water/Dark type for Oshawott.
6: The buff girl is named "Little Bird", apparently, meaning this would likely apply to Rowlet, and make it a grass/fighting type.
1: By process of elimination, this means Damona, the Yokai/Spirit, is applying to Typhlosion, and likely it's form is based on a Yokai. Speculation is generally that it's a ghost type based on some well-known yokai.
For the rest, I'll go left to right and down the list.
2: We already know who Zoro is referencing.
3: The two cloudy hearts are believed to be referencing a new Mythical, which is a wild step to me. It's apparently an entirely new pokemon, so people stopped speculating there.
4: It's a Pokeball Pokemon. Do I need to
tell you what it's likely a reference to?
5: Most people think this is the "Lady Noble" Pokemon Arezu is guarding. Apparently the character is Maki from Love Live, an idol-based japanese anime so speculation is all over the place - Jynx has been mentioned.
6: Already mentioned to be rowlet evo.
7: A cactuar from final fantasy here, also known as a Sabotender. Two speculations here. One, it's a cactus-themed Sudowoodo (as sabotender basically means Cactus pretender). The other is a pun based on the name of Cactuar's signature attack, Thousand Needles (Harisenbon), which is similar to Qwilfish's name as Harisen.
8: A steel type slug or slug-adjacent Pokemon - believed to be potentially Dunsparce.
9: As mentioned, it's Oshawott.
10: This is Project Habbakuk, a plan originally conceived by the brits to make an aircraft carrier from Ice. Avalugg's dex entry suggests it being 'an aircraft carrier made of ice' already. Others suspect it might be a mantine evolution.
11: This is from the manga Esper Mami, with the yokai in question being a kamaitachi - a "Sickle weasel" Yokai. Many thus suspect it to be related to Sneasel.
To expand on this a little further, some may remember a climbing silhouette leaked early on. Other leakers have claimed that is an evolution of sneasel, in which case I will
actually ejaculate because I love sneasel and my biggest issue with it is that it's feather gets ruined by weavile.
12: Apparently this is an ursaring evolution. And it can be ridden. This was confirmed by a different leaker.
To elaborate on Ball Guy Leaks a little more, he's given us some concrete numbers:
7 new pokemon, 17 hisuian forms (unclear if there's overlap)
A line of pokemon will receive a regional form right from the baby stage - it is not Elekid, Magby, Riolu, Chingling, or Munchlax. It's worth noting that the evolved forms of Smoochum, Bonsly, and Mantyke have all been suggested from the riddler's images, and the only sinnoh pokemon
not seen yet include Happiny (but Blissey has been seen) and Togekiss. (the others are Lickylicky, Weavile, Dusknoir and Spiritomb).