The raptor, for sale on Trade Me, was his first sculpture of a dinosaur.
"I was sticking to a lot of Kiwi-type things, because they obviously sell quite well."
But he let his creativity take over as the sculptures became more popular.
"It just kind of snowballed and they started getting bigger and bigger and bigger."
Mr Maddox makes the sculptures using what he calls a "cladding technique".
"It's basically an exoskeleton, that's why you can still lift them."
The hardest part was making them free-standing, which was achieved by strategically using heavy and light pieces of wood for balance, as well as hollow sections, he said.
Mr Maddox and Ms Archer collected driftwood every three weeks - 2.5 tonnes at a time - on trips down the East Cape and towards Taranaki.