Confirming the identity of Jon Snow's mother is huge for any Game of Thrones fan, but we don't know everything just yet. Just as the R+L=J theory has always held, Jon's mother is Lyanna Stark, his father is Rhaegar Targaryen, and Ned is his uncle. What did Lyanna whisper to Ned on Game of Thrones ? Her dying words could fill in the remaining pieces to the puzzle.
HBO's subtitles only give you that she "whispers" and then, "If Robert finds out he'll — you know he will." That's not much. However, with the volume up and my headphones and a few close readings, there is only one major piece of information missing. This is what Lyanna says to Ned:
No, no water. Listen to me, Ned. His name is ... if Robert finds out, he'll kill him. You know he will. You have to protect him. Promise me, Ned. Promise me.
That's a little more, but wait — what is Jon Snow's real name? I think that's the only bit that's unclear. It's possible that she was saying "his name is Targaryen" or "his name is Jon," but since she was completely muffled in that moment, I think the reveal of his true name must be significant. It's possible that Ned renamed the baby Jon, which is unassuming, but his mother named him something else. The only Targaryen name which starts with a "J" that I can find is Jaehaerys — which doesn't seem to fit Jon's personality one bit, if you ask me.
However, if you watch Lyanna's lips when she's whispering, it doesn't look like the name she says starts with "J" at all. It's almost certainly not Jon. It seems likely that Ned named him after his former guardian, Jon Arryn. I don't think Lyanna gave him a Stark name, because Ned seems to understand the significance of Jon just from his hearing his first name. In my opinion, that could also clue Ned in to the fact (which is still just a popular, unconfirmed theory at this point) that Rhaegar and Lyanna ran away together. If she had been kidnapped and raped, I feel she would have given her baby a Stark name. What if she said "His name is Azor Ahai"? That would be wild, and pretty ambitious for a baby name. Rhaegar's children with Elia were named Aegon and Rhaenys. So, looking at Targaryen names, I am going to toss Aerion, Aerys, and Rhaegon into consideration — though my main guess is something like Rhaegard, which combines a bit of House Stark and House Targaryen.
Now, will Jon Snow accept a new name? Probably not. Way back in Season 1, Tyrion Lannister gave him the advice to "Never forget who you are. The rest of the world will not. Wear it like armor, and it can never be used to hurt you." Rhaegar Targaryen was married to Elia Martell at the time of Jon's conception, so he's still a bastard even if he is a Targaryen. After all that he's been through, I don't think Jon Snow would be willing to change the name that has defined him in so many ways.
Images: Helen Sloan/courtesy of HBO; Giphy