A young filly named Applebloom, along with her two friends Sweetie Belle and Scootaloo, embark on a high-seas adventure. But, threats wait at every corner, as Applebloom holds a map to an island FILLED with buried treasure. They were given only one instruction. Beware the three-legged mare.
Based off of Muppet Treasure Island and various versions of Treasure Island
Derpy is Pew? In that case I am going to guess that Pinkie Pie is Long John Silver, since he was a cook which is sort of like being a baker. Twilight is surely Doctor Livesey, and Rarity must be Squire Trelawney.