It's pretty appropriate that frogs are becoming the #antifa mascot when you consider that the main force against the secretly evil King Andreas (a newt) in Amphibia was frogs. :3
From here:
The army continues to grow when Sprig and the others find former enemies like Tritonio Espada and Apothecary Gary, convincing them to join forces to take down the common enemy that is King Andrias and making the Resistance grow each time. When needing to decipher the olm’s prophecy, Sprig and Polly volunteer to lead Sasha and Anne to the olm siblings they encountered at one point, arriving to the city of Proteus to meet Mother Olm, the oldest and wisest of them to learn more about how to stop king Andrias for good. After venturing inside the giant olm’s brain in order to trigger her memory, the old olm tells them about the prophecy and the existence of the Core, and how they need the Calamity Box’s powers in order for king Andrias to be defeated for good. Frog, toads and news continue training in order to be ready to face the king in his castle to claim the box and rescue Marcy, but they need to act fast since king Andrias plans to invade Earth.
Sprig Plantar is the deuteragonist of Amphibia. He is an 11-year-old (10 prior to "Sprig's Birthday") pink frog who is the best friend and guide of the human girl Anne Boonchuy. He is Hop Pop's grandson and Polly's older brother, with whom he resides on the Plantar Farm in Wartwood Swamp, Frog Valley, Amphibia. Prior to Anne's arrival in Amphibia, Sprig had very little if any real friends due to his lack of social intuition and impulsive behavior turning him away from the other children...