The three "Prowler" mounts come in three different colored variates: Ethereal (purple), Ulteran (blue), and Sinister (green), though are much the same, otherwise. Purchasing one of these creatures from the Station Marketplace will set you back 2500SC ($25).
As for stats, Sony Online had this to say about the ride-able beasties:
Each mount comes in your choice of one of the following versions: Fierce and Arcane. The Fierce version increases Slashing, Aggression, Ranged, Piercing and Crushing of caster by 5, while the Arcane version increases Focus, Ordination, Disruption, Subjugation and Ministration of caster by 5. Both versions of the mount have a 65% run speed.
Check out the trailer below for a glimpse of these virtual puppies in action: BOOM video 5100