So I am actually 99% positive this has been suggested before in some fashion, but I have a mighty need for this to exist. There are a few sets of twins around. I personally have two (perhaps three) bred twin pairs: opposite twin girls, and near-identical twin boy/girl siblings. The dynamic for character making becomes a million times easier/better for me personally, and I think twins are just cool in general.
I would love to see a twin potion in the mages brewery. I would be absolutely fine with the potion being "You get a random twin pair in your litter" and have the gender/type of twin be totally random. I would not fuss over a potion that allowed a person to pick what gender/type of twin would come out of the litter either.
I've added a little poll, because I know for myself it's easier to give feedback that way instead of thinking up a reply to support/challenge the suggestion at hand. Although I would also love feedback if anyone has anything they'd like to add!