Yes, Hippo and Snover are banned if you saw the BL/UU sticky.
Swalot is NU due to being completely outclassed by Muk. I agree it isn't terrible, but Muk is just so much better.
&&I think I should go through and respond to people vouching for certain Pokemon. >_<
As for Cloyster, I am also on the fence about it. For the previous poster, its preformance in OU doesn't count at all. I agree with Cynthia that Stealth Rock should be banned from NU due to a lack of viable spinners (currently, only Delibird even learns it). If Stealth Rock is banned, there should be no reason for Cloyster to be in NU, because its weakness to it balances it out a bit (as well as the issue with Spikes and spinning; Toxic Spikes is not an issue for obvious reasons). However, I feel that it is grossly inferior to other bulky Waters with a lack of instant recovery. Corsola can be named a counter with some investment in special defense and STAB special Rock moves, because as mentioned before, Cloyster will have to run a set like Surf/Ice Beam or Shard/HP Grass/Explosion to cover everything, and that's uncommon and a waste of its potential. Wormadam-S, -G, and Minun have their ways of taking it out as well. More than ever before, we also have Pokemon that can take it out offensively, but cannot exactly switch into it, such as Mothim, Plusle and *gulp* possibly Pachirisu and Cherrim if the sun is set up.
At the same time, people have brought up good points, namely decent offenses (particularily base 95 attack and access to Ice Shard). If RD is set up, it can only be revenge killed by Scarf Mothim or Plusle. Its counters are better found in UU, so...the jury's still out on this.
Swalot is NU due to being completely outclassed by Muk. I agree it isn't terrible, but Muk is just so much better.
&&I think I should go through and respond to people vouching for certain Pokemon. >_<
Butterfree is only useful for statusing: nothing else. As a lead, it will either die to Swellow, Scyther or something along those lines, or face something that will just laugh at it and proceed to set up in its face (Persian is a prime example). Even if you argue that it is seeing some use, it is still entirely stoppable. Extremely fragile, predictable, and with the exception of the odd Choice Scarf, remember that Butterfree was also NU last gen before the introduction of Stealth Rock and faster Technician Pokemon.AoK - why is Butterfree on your list of NUs? Thats not true IMO.
While Toxicroak is a good Pokemon and is immune to water moves, 83/65/65 defenses which are rarely invested into don't necessitate it switching in to every threat just because it can resist a move or two.Toxicroak.
As for Cloyster, I am also on the fence about it. For the previous poster, its preformance in OU doesn't count at all. I agree with Cynthia that Stealth Rock should be banned from NU due to a lack of viable spinners (currently, only Delibird even learns it). If Stealth Rock is banned, there should be no reason for Cloyster to be in NU, because its weakness to it balances it out a bit (as well as the issue with Spikes and spinning; Toxic Spikes is not an issue for obvious reasons). However, I feel that it is grossly inferior to other bulky Waters with a lack of instant recovery. Corsola can be named a counter with some investment in special defense and STAB special Rock moves, because as mentioned before, Cloyster will have to run a set like Surf/Ice Beam or Shard/HP Grass/Explosion to cover everything, and that's uncommon and a waste of its potential. Wormadam-S, -G, and Minun have their ways of taking it out as well. More than ever before, we also have Pokemon that can take it out offensively, but cannot exactly switch into it, such as Mothim, Plusle and *gulp* possibly Pachirisu and Cherrim if the sun is set up.
At the same time, people have brought up good points, namely decent offenses (particularily base 95 attack and access to Ice Shard). If RD is set up, it can only be revenge killed by Scarf Mothim or Plusle. Its counters are better found in UU, so...the jury's still out on this.

