Full Pool Party Roster?
So, with the new Pool Party skins coming out in Patch 6.14, I decided to figure out just how many Pool Party skins Riot has been hiding.
Let's start by welcoming Fiora, Miss Fortune, and Taric to the Pool Party Roster. http://i347.photobucket.com/albums/p457/Travis_Coppinger/Fiora_zps6n9quirj.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Miss%20Fortune_zps68wt5fal.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Taric_zpskxssksnl.png Alright, so look at Fiora's Splash art first. Of course we see Fiora front and center. Then we have Darius and Katarina to the left. here's a lady in the back, but we'll get to that later. To the right of Fiora we have that guy in the pack, that's probably Garen. Now the guy on the far left, who is that? First off, look at that symbol on his arm. That is the Freljordian symbol for the members of Avarosa. Who makes up the group with these symbols? Well there's Ashe, Anivia, Gragas, Nunu and Tryndamere. Now of those few, who has long hair in every skin he has? That person is none other than Pool Party Tryndamere. Lets move on to Miss Fortune's splash art. So first we see Miss Fortune to the right, then going from right to left, Lee Sin, Blitzcrank, blonde lady, and Dr.Mundo. We will be looking into blonde lady later. There's not any surprises in the background sadly. Next is Taric's splash art. First, we have Taric in front, then from left to right we have that purple blob (which might be Zac or a bunch of pool floats), then we have Miss Fortune, a bald man which is most definitely Braum, then Fiora, and finally a spiky haired man who has been in many Pool Party splash arts, Darius. Also, something I noticed after editing the pictures, there is a banner in the air under Taric's arm. It's a banner with Pool Party Draven on it. Go figure.
Alright so with the new members out of the way, lets start from the beginning with Renekton, Leona, Lee Sin, and Graves and Ziggs, along with the splash art containing these 5 champions. http://i347.photobucket.com/albums/p457/Travis_Coppinger/Pool%20Party%201_zpsckcknaqp.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Renekton_zpswv90s92l.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Leona_zpsby21r6x2.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Lee%20Sin_zpst6zaagbg.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Graves_zpshvaaqrqv.png http://i347.photobucket.com/albums/p457/Travis_Coppinger/Ziggs_zpshmgbf5sf.png Lets start with the complete set of 5. Starting from the right, we have Ziggs, Leona, Renekton, Graves, Blonde Lady, Morgana way in the back, Ahri, and Vayne, and tattoo girl throwing the peace sign. Referring to a couple of her skins, the lady farthest to the left is Vayne. Then we have the tattoo girl. The only champion in the game with a sleeve tattoo in all her skins is Jinx. Now we still don't know who exactly blonde lady is, but things will clear up soon. Next is Renekton's splash art. From the right, we see Renekton, Zac, Ahri, and Ziggs. Jumping off the lowest diving board looks like a preying mantis, which seems to be Kha'Zix. Behind him are 3 shaded figures. The first one has a big cylinder, which is Ryze's thing on his back. The second shaded figure looks to be yordle size, and according to some of his skins, Teemo has a little strand of hair standing from the top of his head, so that figure is Teemo. The final shaded figure looks like another Kha'Zix? unlikely, so lets move on. On the top diving board, we have the fat man that goes by the name of Gragas, and a yordle with a pointy hat. Looks to be Lulu as confirmed in the second set of pool party skins. In Leona's splash art, we see from right to left, Ezreal, Nami, Leona, and old Taric maybe? Then there is blonde lady again with darker orange-like hair. Has Riot been planning to have a Pool Party Taric since the Pool Party's first release? Maybe that's what pushed them to rework Taric. Not much else in this picture other than alot of Fiora's crabs. Within Lee Sin's splash art we see a couple of ladies. From left to right, we see Orianna, Lee Sin, and a lady with face tattoos and a furry bra. With the dark brown hair, this seems to be Nidalee. Not much else here. Now in Graves's splash art we see alot of skins in the background. Starting from the right, we see Graves, then we go to the very back to see spiky haired Darius, a big buff man with short brown hair, looks to be Garen, then we see Katarina to Garen's left. In the air is Ziggs being watched by Renekton in the lifeguard tower. Then on the diving board is Aatrox, which looks to match the final shaded figure from Renekton's splash art. Then just below the Aatrox box there is something blue there. From afar that looks like a blue penguin, but I want you guys to zoom in. Now to me, that is either left shark, or the only champion with blue hair in this game. That champion has to be Jinx hiding among the diving board. This is confirms the sleeve tattoos in the group pool party picture. Rounding off the original 5, we have Ziggs. Starting from the left, we have Ahri, then up top we have Renekton's feet. In the water we have Garen, Katarina, and Darius, all being invaded by Ziggs. Now who are those people in the back? The lady on the left is Leona, the next lady is definitely Diana with the hair style, then we have a black champion with white hair. We don't have one of those... or do we. On the other side of the Diving board we have Xin Zhao. Now who is that in between Katarina and Darius? They have a shaded face, a straw hat and green, muscular limbs. In Chinese splash arts of Karthus don't show his skull complexion, but last I knew karthus didn't have hulk like arms. Other options could be Toxic Mundo, but I'm not quite sure about this one. Rammus maybe?
Alright, so with the original 5 down, lets go the the second installation of the Pool Partyers with Draven, Rek'Sai, Dr.Mundo, Lulu and Zac. There is only one image and it simply only has the 5 (plus a cute little seal) http://i347.photobucket.com/albums/p457/Travis_Coppinger/Pool%20Party%202_zpshtvdssvc.png
Alright, so will all the splash arts down, lets go back to a couple of figures that we haven't looked into yet. First we have Blonde haired lady featured in many of the splash arts. She was first seen in the original installment of the pool party gang and she just seems to be having a good time. She is seen again in Leona's splash art. Now I want you guys to look at blonde lady. In all the pictures she is in, one of them stands out. In Leona's splash art the bathing suit is a darker shade of blue, and the hair is a slightly darker shade, almost looking orange. I think, these two blonde ladies are two different champions. Lets focus on the one featured in Leona's splash art. This lady has darker hair and suit. Now I think we can get a pretty good guess at who this is by Ezreal's actions in this splash art. He looks angry, and jealous. He seems to be giving a side eye to that guy chasing blonde lady. Do we know of anyone Ezreal likes? Yes actually. We know that Ezreal likes Lux. Could this splash art be showing Ezreal's jealousy towards Taric for stealing his girl? I think so. So with that blonde lady out of the way, we now have the other lady who is in many of the other splash arts, including Miss Fortune, and the group splash art of the original 5. Now this lady has much blonder hair, and a lighter blue suit. Who do we know has that same description. I say, we have Janna. In her original splash art, her hair is a light blonde color, and her suit could be a new outfit. Since many of these Pool Partyers have completely new color schemes, this isn't that far of a stretch. With the blonde haired ladies out of the way, we now move onto the white haired ladies. First, we know that they are two different white haired ladies, mainly because one is white while the other is black. Knowing it's two different ladies, lets look at the lady shown in Fiora's splash art. This lady has a white suit with some red markings, that resembles a flame, on bra. After shuffling through some skins, I found this picture. https://dncache-mauganscorp.netdna-ssl.com/thumbseg/1307/1307163-bigthumbnail.jpg
Those markings look surprisingly similar to the ones on the bra. I think we can safely assume that this white haired lady is Ashe.
Now onto the final mystery person, the white haired lady in the Ziggs splash art. Now there is something interesting with this lady. First of all she is black, and Riot only has a few black ladies in the roster (Illaoi and Karma for the ladies). There has been one more black lady introduces very recently, but Riot couldn't have had Taliyah in mind with the first installment of the Pool Party gang could they? All that put aside, I want to focus on the hair style, and the color of her hair and her facial structure. First, her chin is very rounded, much like Taliyah's is in her original splash art. "But her hair is brown in her original splash art." I hear you say. Well take a look at this! http://i347.photobucket.com/albums/p457/Travis_Coppinger/Taliyah_zpsubd706hx.png
This is Taliyah's Freljord skin where her hair is white, and done in the exact same way as in Ziggs's splash art. had Riot seriously had Taliyah in their mind since 2013? Has Taliyah's model been in Riot studios for three years. I think its a possibility.
So with all that done, lets line up the roster:

That's 36 champions that are a part of the Pool Party gang. There is a 37th member, but that pool cleaner showcased in Ziggs's splash art could be Rammus, but it's unlikely. With a total of 36 known members that's 23 members without skins. I think Riot has alot of work next summer.
Thank you all for reading this post, this took alot of time to put together (about 3 or so hours) so excuse me if there's some grammatical errors or something along those lines. I hope you all have a joy in reading this, and I hope you all have a wonderful day! <3 :D
(A few hours later) So after a couple of hours there has been some very good feed back about a few mistakes I may have made, and the mystery shaded champion has been revealed as Yorick. I hadn't thought of yorick, and it makes alot of sense. Pool floats instead of ghouls? I think so. I have also missed a little pool party Lulu in Taric's splash art. I was so busy looking at the blob I thought could be Zac, that I didn't bother to look up.
Now I want to move onto some of the other mistakes with the blonde haired ladies, and the white haired ladies. It has been said that all the Blonde ladies are lux. After a second look through, I missed one very key feature in all of this. What does Janna have in almost every skin she has? Big, elf-like ears. In Leona's splash art, we can see the ears are human like. Sadly in the other splash arts, the ears are hidden making me believe this is also Lux. Unless It's Forecast Janna, which it could be seeing that Forecast Janna and the first set of pool party skins was released in the same year (2013). I will keep this as a possibility, and I will keep Janna in the roster because more possible skins, why not.
Now we have the white haired lady. It has been said that this is old Riven and not Taliyah. This makes sense, but to me the skin tone is still too dark to be Riven. it could very well be a tanned old Riven, but we aren't for sure if they've had Taliyah's character model for a while, for whenever they wanted to put the model to use. I will add Riven to the roster, but I will also keep Taliyah in there, for again more skins.
I also left out Teemo in the first roster count, but now there is a total of 39 Pool Party members. I want to thank you all for pointing out a few of these errors, and adding to the roster!
New Roster:

on the lifesaver chair
behind him