By early afternoon, Merlin already has a packed schedule behind him.

After spending the morning at Mexico's largest television station, the two-year-old viral duck moves on to a string of media appearances before ending the day among thousands of football supporters at the World Cup Fan Fest in Mexico City.

For most ducks, that would be an unusual day. For Merlin, it has become normal.

The viral duck captured the attention of millions across Mexico after a video showed him walking down a city street beside his owner while dressed in Mexico's green national team jersey.

What began as an ordinary walk quickly turned him into one of the country's most unexpected World Cup sensations.

The duck winning over football fans

Merlin's popularity has spread far beyond social media.

FIFA has referred to him as Mexico's "ambassador", while Mexico's national team joined the fun by sharing an image of the duck soaring above the stadium in Guadalajara, where the side faced South Korea in its second match of the tournament.

His shirt carries the number 12, a number that has become closely associated with his growing fan base.

Across the country, bakers have even created pastries inspired by Merlin's appearance in his green jersey. Television programmes invite him on air for his thoughts on the World Cup.

His match predictions rarely change.

"Quack, quack, quack."

The video that started it all

Karla Ivette Gomez, a 48-year-old street vendor, still finds the attention surprising.

Speaking outside Mexico City's historic Bellas Artes Palace while journalists crowded around Merlin with cameras and microphones, she recalled the moment everything changed.

"At no point did we think he would go so viral," she said.

According to Gomez, the breakthrough happened during a routine walk along one of the capital's main streets.

"We were walking down the road and out of nowhere a girl takes a video, and that's when we went viral," she explained.

In that now-famous clip, Gomez can be seen pushing a juice cart alongside her son while Merlin hurries to keep pace behind them.

His wings stay tucked neatly inside his shirt as he waddles along.

World Cup fever takes hold

Merlin's rise reflects the excitement surrounding the World Cup in Mexico.

The tournament has inspired unusual displays of support across the country. Among them is a statue of Jesus inside Mexico City's cathedral, dressed in the national team's jersey.

Yet few symbols of football fever have attracted as much attention as the duck in green.

'He's part of the family'

When Merlin arrives at Bellas Artes Palace, recognition comes instantly.

"It's the duck!" one man shouts.

Within moments, people gather around him, eager to take photographs, record videos and gently stroke the famous bird.

For the Gomez family, however, Merlin is much more than a public attraction.

He is their third duck. A customer gifted him to the family after the death of their previous duck. His name comes from the legendary wizard of medieval mythology.

"He's part of the family," said 14-year-old Cristian Gomez, who looks after him.

His mother agrees.

"He's our everything," she said.

The family travels prepared, carrying water and spare clothes for their unusual companion. They occasionally remove his jersey to allow him to rest comfortably and stretch his wings.

A diet that includes the occasional taco

Merlin's menu is varied.

He eats fruit, vegetables, crickets and fish. Every so often, he is also treated to a taco.

Karla admits the indulgence may have had consequences.

During a recent veterinary check-up, she said, the doctor informed her that Merlin was carrying a little too much weight.

"He said he's overweight, he's fat," she admitted.

Heading for the fan fest

The duck's next destination is the fan zone, where thousands of supporters gather despite the rain to watch the match.

Many are also hoping to catch a glimpse of Merlin.

The Gomez family says FIFA plans to recognise him as an ambassador in Mexico, an honour that has become a source of pride.

"They're going to name him FIFA's ambassador in Mexico," Gomez said. "We're very proud of the mention."

Following a World Cup tradition

Merlin joins a long line of animals linked to football tournaments.

World Cups have often featured animal predictors, perhaps most famously Paul the Octopus, who became an international sensation during the 2010 tournament in South Africa.

Mexico has seen similar efforts before. At Guadalajara Zoo, elephants, gorillas and even a puma have been involved in predicting match results.

Whether Merlin's forecasts prove accurate remains to be seen.

For now, his simple prediction of "quack, quack, quack" appears to be more than enough to keep football fans entertained.