Happy Ghast rain speed bonus.

Happy Ghast could be faster while rain and thunderstorms, this little dude literally back to life from water, soo may he be faster while water goes from above? Now Happy Ghast good type of vehicle with big potential, but for regular player he really slow while exploring the world, it would be ballanced becouse rain and thunderstorms not soo regular and it would be great surprise for player while flying for a long distanse. Speed bonus could work while player mounting Ghast, it could be seen with some particles or change of Ghast voice, othervice Ghast behave normal while rain with some voice change and without speed boost while player not mounting him.                                                                                                           

Make Happy Ghast more happier in otherworld!