'Wallace' is a giant weta, constructed from native wood dredged from the bottom of Lake Brunner by a family friend.
His WoW blurb explains: "Timber dredged from the lake of childhood summers transformed into what lurks in dark spaces."
The rimu, matai and kahikatea logs had been submerged in the lake depths for 80 years before the transformed timbers took to the stage in front of a select audience and judges in Wellington on Friday last week.
The internal frame is constructed from aluminium and fibreglass, while everything visible is wood and, instead of the usual upright presentation, "was the only one where the model lies down for the show".
Admitting he built the model around his own bodily dimensions, Mr McMillan said: "You get in pretty easy, you just lift up one of the legs and slide in. It is wheeled and you drag it round.
"You always bank on your stuff being the best, but in the judges' eyes, you wouldn't know which way it goes."
The Friday night judging was the culmination of lengthy preparation.
"It was pretty nerve-wracking seeing it up on stage and hoping it would stay together and nothing weird would happen with it -- I tried to make it pretty sturdy.
"It's pretty good, I made something worthwhile."
This was not his first time on the WoW stage, having placed third in the 2017 science fiction category with Watcher in the Water, which can still be seen on display at the family firm, Dispatch and Garlick Engineering in Greymouth.
As for 'Wallace', it remains in Wellington under ownership of the WoW organisers.
"It's quite big, a bit big for them to store. It might even go to the Nelson headquarters yet."
His winners purse was $6000, which Mr McMillan welcomes.
"I don't sell anything I make so it's good to get a bit of money back for something."
As for mingling with the fellow entrants: "We had a designers' day and I had a yarn with a few others, but I'm a bit like 'Wallace' - I'm happy to sit in the corner and hide out."
- By Meg Fulford
