It's five days of hedonistic revelry in Rio, where the King Momo takes the keys of the city and officially declares joy with the opening of the city's legendary carnival.
Wilson Dias da Costa Neto, a smiling, moonfaced 27-year-old chosen as this year's Momo, swept in by limousine flanked by the carnival queen and two princesses to assume his festive reign.
"In the name of the prefecture and as the monarch of the world's largest street festival, I decree joy," Momo beamed.
Mayor Eduardo Paes joked as he passed him the keys: "I hope you'll be able to sort out the city center's problems with automobile traffic!"
In reality, within hours, the city's streets will be so clogged with a gyrating mass of samba drummers and sequinned dancers that cars will for once be forced to take a back seat.
This year's festivities are set to be even more frenzied than usual as Brazil prepares to host the World Cup for a month from June 12.
"Finally, it's carnival!" blared the Globo daily as the phoney war gave way to a flurry of activity as the final touches were put to the spectacular floats which will glide through the city from early Saturday, when Cordão da Bola Preta, Rio's oldest group founded in 1918, will parade before an estimated 1.8 million people.
- Beatlemania... samba-style -
Dozens of other blocos will parade in different parts of town across the five days -- including Sargento Pimenta (Sergeant Pepper), who will Monday pound out Beatles music to a samba beat.
A dozen samba schools will compete Sunday and Monday in the Special Parade, which will draw around 70,000 spectators to the city's fabled Sambadrome.
Some 30,000 people were set to watch parades in the business hub Sao Paulo, more staid than Rio but catching pre-World Cup fever -- the giant city will stage the June 12 opening match.
Rio's top samba schools, each comprising thousands of performers, will parade along the 700-meter (yard) Marqués de Sapucai avenue leading to the Sambadrome designed by celebrated Brazilian architect Oscar Niemeyer.
Adding to the millions of local revelers, city hall expects more than 900,000 tourists to throng the jam-packed streets -- some two percent more than last year -- with revenues forecast at around $400 million.
They will more than make up for those residents who pack their bags at this time of year to escape the constant din.
Sporadic public protests in recent months against political corruption and the multibillion cost of the World Cup have prompted police to step up security in Rio, which will host seven World Cup matches, including the July 13 final.
Thursday, the eve of the carnival, had seen the Ocupa Carnaval pressure group hold a spoof mini-carnival while the Banda da Rua do Mercado bloco held a topless march with actress Ana Paula Goncalves Nogueira, suitably unrobed, at its head.
Some in the Ocupa Carnaval group held aloft giant puppets representing city rulers, their pockets stuffed with money; others linked arms with the tentacles of a huge black model octopus representing the long reach of corrupt politicians.
"But tomorrow's carnival and that is sacred. There won't be protests -- it's a valve to let out the frustration with politics," one local, Reinaldo Alves dos Santos, told AFP.
- Nationwide fever -
By Sunday night, some four million people will have let their hair down and many will carry on through Tuesday's official close and beyond.
Brazil's passion for carnival was also enveloping the northeastern city of Salvador de Bahia, the cradle of Brazil's African heritage, where huge blocos have since Wednesday been parading in the paved streets of the city's old town.
Further north, Recife and neighboring Olinda are hosting thousands of dancers performing the "frevo", a rhythm inspired by martial arts-cum-dance capoeira, led by the "Galo de Madrugada" (morning cockerel) troupe.
In a nod to the World Cup, one Sao Paulo school was honoring 2002 world champion Ronaldo and another in Rio chose 1980s star Zico as its theme.