I measured the box and it's 39.5 cm x 30 cm x 12.5 cm. (Or for the metrically impaired - 15.5 inches x 11.75 inches x 5 inches)
I don't have a scale that will weigh the dragon. (And I just tried standing on my scale with him in my hand - and then without him - to see if there was a difference. The weights were the same. Sorry.)