Fans may not remember, unless they have been marathoning the past seasons in preparation for the upcoming season, that in episode 12 of season one of "Once Upon a Time" entitled "Skin Deep," Regina visits Rumpelstiltskin after he releases Belle and says that she wants to make a deal with a mermaid.
There is no saying what kind of a deal that Regina would make with a mermaid, but it does allude to the fact that she already knows at least one and it is more than likely Ariel. However, Edward Kitsis has already shared that there will be more than one, they just won't be as nice as Ariel.
Ariel is expected to make her first appearance in the self titled episode three of "Once Upon a Time" season three called "Ariel." At this point, fans are unsure as to how big of a story arc she will have or whether she plays an integral roll in the overall story, but she will be in-depth enough that we will meet Ursela as well as some of the other mermaids that may be Ariel's sister if the story follows the Disney version.
What kind of deal do you think Regina could have possibly made with a mermaid?