Dottie is the last Pixl you can get however there are 3 other Pixls that you have the option to get,they are Barry(Which you can get by going back to Chapter 3 where you meet him),Dashell(To get him you will need to complete The Flipside Pit of 100 Trials)and Piccolo(To get her,you will need to complete a prolonged trading sequence and after that you will get a key to unlock a door in Flipside).