BUENOS AIRES (Reuters) - Argentine President Javier Milei looked more like a rock star than an economist-turned-politician on stage Wednesday night.

Wild-haired, clad in a black leather coat and jumping around as audience members waved and shouted, Milei belted out his version of the song "Panic Show," by Argentine band La Renga, ahead of the launch of his latest book.

"I'm the king. I'm the lion!" Milei shouted.

The libertarian leader, who took office in December, often depicts himself as a lion, fierce in slashing the South American nation's budget and trampling political conventions.

"I eat the elite for breakfast!" Milei continued, playing on the song's lyrics.

Milei has often targeted the political elite, whom he refers to as the "caste" that caused Argentina's economy to slide and inflation to balloon into the triple digits. 

Critics of Milei, including opposition politicians, panned Wednesday's performance as cavalier at a time when Argentines are struggling to get by under his tight fiscal policy.

Poverty has crept up to nearly 60% under Milei's administration and layoffs are growing.

The president still has his fans, however. 

He is more than a traditional politician, 23-year-old student Leonel Grillo said ahead of the show. "That's why people love him - he's a great politician but also a great showman."

Milei performed in front of 8,000 people at Luna Park - a historic Buenos Aires venue - flanked by a party lawmaker on drums and his personal biographer on bass. 

The president often sang at campaign events, and once caused a national stir for dressing up as an "anarcho-capitalist superhero" at an anime convention.

After the number, the event turned into a more-traditional book launch for Milei's "Capitalism, Socialism and the Neoclassical Trap."

Journalists accused the far-right libertarian of committing plagiarism in parts of the text, though Milei spokesperson Manuel Adorni denied the reports on Tuesday. 

(Reporting by Candelaria Grimberg; Writing by Maximilian Heath and Kylie Madry; Editing by Stephen Coates)

By Candelaria Grimberg