There is no official word on these droids yet.

Above is the Destroyer Droid. You may remember an old report by Bothan Spy from November of 97 on this site referring to it.:

"There are also "Destroyer Droids", which 'roll' into the hanger. They then open out, rather like an earwig, into a mean, black, tripod robot with guns for hands."

As Bothan reported, they roll up into a ball and roll around. Kind of like a Transformer, eh? Anyway, they come in several color variations. Dark bronze, black, and gold.