This puzzle type is called "Slalom," and it's probably the best thematic fit so far, a race-themed puzzle for a pony who loves to go fast. Composition was a pain, though. (Had to get it just perfect.)
The object is to draw a loop that goes from square to edge-adjacent square, starting and ending at the checkered square and crossing every hurdle once in order. "Crossing" means starting on one side of a hurdle, taking two consecutive steps perpendicular to it, and ending up on the other side of the hurdle. There are 26 hurdles here, labeled A-Z; ten labels are shown here.
Normally, labels are numbers, and the number of hurdles is given on the equivalent of my checkered square. I felt all right giving the count outside--though actually, there's a little room for that under the grid if this way is too obtuse--because W is so close to the end of the alphabet, so it should be pretty obvious. Also, hurdles are traditionally bracketed on both ends by black blocks (which cannot be traveled over, in the vanishingly slim case that this wasn't guessed), but that obviously crowds grids and would have interfered with the tight theming.
Okay, that leaves AJ, Fluttershy, and Twilight. I can definitely get this done before the end of the TV series, no problem.