PHILADELPHIA – Las Vegas favored the Vikings but didn't do them any favors.

As three-point home underdogs in Sunday's NFC Championship Game, the Eagles' electric battle cry is alive, well and will be punctuated by a rabid crowd that's coming armed with attitude, decibels, dog masks and shirts that scream, "HOME 'DOG GONNA EAT."

"I didn't think it would take off like this," said veteran defensive end Chris Long, who hatched the NFL's latest craze when he and right tackle Lane Johnson donned German shepherd masks on the field after the Eagles upset the favored Falcons at Lincoln Financial Field in last week's divisional playoff game.

Boy, was Long wrong.

Amazon, where Long purchased the masks, ran out of them early in the week. Later in the week, D&J Costumes on Frankford Avenue told the Philadelphia Inquirer that it was taking orders by phone — people still talk on phones? — with game-day delivery guaranteed.

Meanwhile, fans were calling the Eagles wanting to know whether dog masks are allowed in NFL stadiums. Like the rest of the world, they obviously don't watch Browns games.

The Eagles tweeted that masks are allowed but can't be worn through security. Lord help those poor bomb-sniffing literal canines when they get a load of what's coming through the gates on Sunday.

"I think it's funny," said linebacker Nigel Bradham. "It's going to be so cool to see the whole Linc filled with dog masks."

About eight or nine days ago, Long was talking to Johnson when he pitched the idea of dog masks. With quarterback Carson Wentz out for the season because of a knee injury, the Eagles became the first No. 1 seed to start the playoffs as a home underdog.

"It's funny because the media here was just jamming this narrative down our throat and hitting us over the head with it every day," Long said. "I told Lane, 'Wouldn't it be funny if we got some dog masks and put them on if we win?' "

Why German shepherd masks? Couldn't you, um, buy American?

"I went with the mask that would show up the quickest," Long said. "The German shepherd won."

Long, who donated his entire salary this season to charitable causes, considers the whole thing clean fun that also led to an unexpected boost for Johnson's foundation.

"It was Lane's foundation that came up with the idea to sell the shirts," Long said.

By Thursday afternoon, the foundation had sold more than 5,000 shirts and raised more than $100,000 for Philadelphia's public schools, according to Johnson.

"We got great fans in Philly," said Long, who won the Super Bowl with the Patriots last year. "When they get an idea that something is going on, they go all in. It's pretty awesome to see."

When game day finally arrives, one of two NFL firsts will happen, depending on the game's outcome.

The Vikings win and they play the Super Bowl in their own stadium.

Or …

The Vikings lose and a pack of dogs will follow them home, frolic in their streets for a week, and soil their stadium in front of about 111 million people on Super Bowl Sunday.

"We don't mind being the underdog," rookie running back Corey Clement said. "I'd rather shock the world than the world already be on notice that I'm coming. It gives us more fuel to our fire. There's a level of disrespect being thrown onto our names. And that's a good thing."

Since 1990, the Eagles are the fifth top seed to play a conference title game as an underdog. Only the Broncos in January 2016 went on to win.

But, in franchise history, the Eagles are 4-0 as a home playoff underdog.

What will happen? Doggone if I know, but the possibility of dog masks invading downtown Minneapolis for Super Bowl LII does exist, people.

"If that happened, I wouldn't mind getting one myself," Clement said. "That would be pretty cool."