Thank you for the correction. I have amended the title: I chose the clumsy common name from the Zoo's Annual Report rather than Zootierliste's 'Gariau forest dragon', but I don't like either much.
I thought trusting the label might be a mistake, and a Google search didn't really help. I get confused by agamids
I've seen them for sale under the name 'New Guinea Forest Dragon', which, while not uniquely applicable to H. magnus, is a much more sensible name in my opinion.