I wanted something easy to make since I was super swamped that week so I googled pony cakes and found this gem over at Betty Crocker it was really easy to make and they gave me the paper templates to print off. I just layed them down on the cake and cut around it. I base frosted the cake (thin out your frosting until it can be poured on and frost all sides and top), refridgerated it then frosted the rest of the cake. The saddle, #5 and piping around the saddle are fondant. I used the white frosting (colored pink, orange, green and purple) then I used the technique shown over at Karen's cookies for easy piping bag clean up and placed all of the frosting on syran wrap in long snake like shapes that touched and were stacked on top of one another and closed that up and dropped it in the piping bag. I used a plain round tip to pipe the mane, tail and hooves on. I also did the sides of the tail, bottom of the tail etc. The eye was a piece of black fondant-(Speaking from the expience of my friends it is best you don't eat too much black fondant)
You can also use the technique shown here to create a swirl effect of the colors shown above but for me it uses to many bags creates, too much waste and a lot more clean up.