I'm not sure if this is even a succulent. At least to me, it doesn't match any succulent that im aware of. What I can tell you is that a hybrid between a bryophyllum and a haworthia is impossible, as they are not the slightest bit related. Try the 'Name that plant" forum on gardenweb.

Could it be Plectranthus prostratus?

There are tiny succulents native to Australia. They can often be seen along the sides of roads that have been cleared. I did not know this until attending a lecture about the native succulents of Australia. Perhaps it is one of those?