Some info on certain sites have referred to a character I do not recall seeing during Finding Dory.
“Kate McKinnon as Inez, a pelagic sea snake”
It also lists Bill Hader as a narwhal, where in the movie he played the onscreen husband of Kate’s character.
I checked IMDb’s full cast list to confirm this role and it lists Kate’s role as “Wife Fish”.
So where did this info come from?
And is it genuine?
Given the lack of supporting evidence discovered so far, I am suspecting this is false info.
There’s no such thing as sea snakes…that’s false info right there. Whoever tried to say that was obviously just trying to trick us into giving them attention…people on the Internet just like to claim that what they think is right just to get attention, and spreading a bunch of lies is certainly not the best way to do it. (They really need to get a life, come on!) 
Actually, sea snakes are very real:
[url]http://www.mesa.edu.au/sea_snakes/sea_snakes02.asp[/url]
I have personally seen this snake for myself in Melbourne aquarium.
And given that this movie is based around Australian marine life, a sea snake as a character would not be unexpected.
But if you meant that there are no sea snakes in Finding Dory, that would be correct.
I think it was just a case of wikia vandalism, there are people who keep inserting false info, sometimes just to prank, but most often to represent their “head canoning” as established fact to those who do not know better.
I have to keep deleting their edits whenever I find them because of this.
And sorry for reviving the thread, it just took me a while to realize it had gotten a reply.