Basicaly, it's like the speeders exceept it's on star wars creatures such as-
Condor dragon
Mygeetoan yaks
and so on
you would have to trian the ability but it would be more expensive and only unlocked at level 50 also when mounted each cresture can have a little attack but it wouldget bigger and smaller depending on the price so high attacks would be more credits low attacks would be less credits and so on because of the attacks I would make the Creatures move slower than the speeders as then everyone would just go for the creatures!
Just An Idea