In his first court appearance since ending a three-week hunger strike, Kremlin critic Alexey Navalny called Russian President Vladimir Putin a "naked, thieving king."
Navalny appeared Thursday in a video link from prison to a Moscow courtroom where he was appealing a guilty verdict for defaming a World War 2 veteran.
According to news reports, Navalny appeared thin, and his head was shaved.
"I looked in the mirror. Of course, I'm just a dreadful skeleton," he said.
Navalny began his hunger strike March 3 and ended it April 23.
Later in Thursday's hearing, he took the opportunity to attack Putin.
"I want to tell the dear court that your king is naked," he said of Putin. "Millions of people are already shouting about it, because it is obvious. ... His crown is hanging and slipping."
He also reiterated his claim of innocence on the embezzlement allegations that ostensibly landed him in prison.
"Your naked, thieving king wants to continue to rule until the end. ... Another 10 years will come, a stolen decade will come," Navalny said referring to Putin.
Last week, authorities in Russia disbanded several regional offices of Navalny's anti-corruption group, the Anti-Corruption Foundation. A Russian court is considering branding the group extremist.
Last week, more than 1,900 Navalny supporters were detained during protests in cities across the country. From his Instagram account, he said he felt "pride and hope" after learning about the protests.
Navalny survived a near-fatal poisoning last year and was arrested when he returned to Moscow in January following lifesaving treatment in Germany. The Kremlin denies any role in the poisoning.
He was sentenced to two-and-a-half years in prison in February on an embezzlement charge and was being held at the Pokrov correctional colony, which he described as "a real concentration camp."
The United States and other countries have sanctioned Kremlin officials over the poisoning, and many are calling for Navalny's release.