"I thought it'd be quite easy to complete, especially because we put the call out at work to see who else has got them and to bring them in," Winstanley said.
"We had a little opening ceremony when I got home each night from various people. It was all very exciting until we suddenly realised we were missing one.
"That was Mr Incredible."
Countdown shoppers who spent $30 would be given a collectible tile with a Disney Pixar character on them from across 11 different movies.
The tile featured a character on one side and a letter on the other, the collection including the alphabet, punctuation marks and other symbols.
The collectables weren't something Winstanley thought his two young children, aged 3 and 1, would get into - but he was wrong.
"My daughter loves them, loves them! And so we then got to the stage where she wanted to complete the full 36," he said.
"Basically, we've got two full sets plus another 70 spares so we could have another two sets on top of that and still, no Mr Incredible.
"One of my best mates at work, he's got two boys and he has got two full sets but no Mr Incredible. Where is Mr Incredible?!"
A spokeswoman for Countdown said they had it on "good authority" all the tiles of the Disney Word set were evenly circulated.
"The tiles have been sent to stores in random numbers, even our teams are unsure of the treasures that hide within the wrappings," she said.
"Part of the joy of collectables is the challenge to be able to complete the entire set."
Anyone who was still hunting for any elusive tiles was told to attend the upcoming swap day held at Countdown stores nationwide.
On Saturday next weekend, October 26, Countdown stores would be hosting swap days where people could try and find their hidden characters.
