I found a Begonia 'Tiger Paws' Sue, I wonder if it's the same plant, or from the same breeding for sure.
http://apps.rhs.org.uk/plantse...
Both are listed in the RHS..
http://apps.rhs.org.uk/rhsplan...
I found another similar one, Begonia 'Leprechaun'
http://www.anniesannuals.com/p...
http://www.kartuz.com/pc/20369...
Leprechaun looks closest of all. And I have been on another plant lust journey!