Seven years after the show, and things have changed. Starlight married her childhood sweetheart, and now they're having a foal of their own. Dark forces are aligning though, and they're targeted by an enemy that no-one could have predicted. Fortunately, an equally unpredictable ally has also arrived, and is ready to fight to protect them. Luna and the mysterious stranger must work together to defeat their insane attacker.
AU tag because I'm ignoring the Season 6 finale and because of the reveal at the very end. Additional character tags (yes the spoiler cover is for a reason): Star Swirl
Chapters (1)
I kind of like mearhwolf myself (mostly because it's almost 'marewolf', for maximum confusion
), but horswolf seems no less valid a construction. 
7846897 That is a punnier construction, I like it.