Link and Epona share a powerful bond, through out Ocarina of Time, Majora's Mask, and Twilight Princess. If Epona were to enter Equestria alongside Link, the results might be interesting.

If this is following he events of Ocarina of Time, and/or Majora's Mask Link might be incredibly surprised if his trusty steed could speak. As for this version of Epona, Link has been very friendly to her as a child, and freed her from Lon Lon Ranch when it was taken over by Ingo, who tried to tame her for Ganondorf to ride.
If this is after Twilight Princess, Link could talk to animals, including Epona while he is in his wolf form. (Though she does not say much in game) Link used Epona even before he needed her to battle, they both herded goats together! Link might be confused if he could understand Epona in his Human form, but he would certainly be used to doing in general.
In both lifetimes they were great companions to the end, and shared a strong bond with eachother!

Also, some interestinig trivia that can definatly be used in a story, Epona is the name of the Celtic Goddess of Horses and Fertility.

So for all I know, Epona may be destined to grow wings and/or become a legitimate alicorn! (No not for the mere sake of making fun of Alicorn Twilight )

Epona also seems to like those with a kind heart, and great singing like Malon, Romani, Fluttershy, Sweetie Belle, and possibly some other characters.

Now I leave you with an epic picture!

Powerpuff Link??? Hey if it is Faust and or Craig its good enough for me!

ok this sounds like win (even the becoming a alicorn part), I think someone should do it

1806530 so possible goddess of equestria the maker of ponies

All my yes. When do we start?