With the success of the C4T-Series Protocol Droid, the engineers at Serv-O-Droid Inc. decided to take it to another level and scale up. The R&D took to the Canine form as it provided versatility, speed, and the asthetic of "mans best friend". When the DO6 Protocol Droid rolled out it became a hit among those who wanted a dog but could not afford the maintenance of an organic animal. It has been especially popular for people/species who are allergic to the animal! There have been reports that without the occasional memory wipe the D06 can gain a personality of its own depending on the treatment of its master...or even lack thereof. There has also been some rumors that some select few figured out that unlike the delicate C4T, the D06 can be modified for more than its original intent...
Unmodified, the D06 is legal in most regions of the Galaxy.
To create a robo canine companion for all those wandering heroes who just want a buddy! It is basically a reskin of the H7D Series Protocol Droid