Crayon Shin-chan: Roar! Kasukabe Animal Kingdom (2009) on Netflix

Plot summary

Mamoru Shizime, the new mayor of Kasukabe, launches a set of ecology activities for the city. Down at the riverbank, Shinnosuke Nohara finds a small bottle holding a light green liquid and brings it home. That night his father Hiroshi and his mother Misae drink from it by mistake, and over time their bodies change into animals: Hiroshi becomes a rooster and Misae a leopardess. When Shinnosuke's friends come to visit, a gang of strangers under a man called Bunbetsu appears and tries to seize the family. The attempt fails, and the Noharas escape with help from a woman named Victoria.