In the movie "Ant-Man" directed by Peyton Reed, the animal that Darren Cross, the main antagonist of the movie, unsuccessfully tried to shrink was a lamb. Cross was trying to replicate the technology developed by former S.H.I.E.L.D. agent Hank Pym to harness the ability to shrink objects by reducing the space between atoms. Cross had a prototype suit that allowed him to shrink and in his first successful test, he shrunk a keychain to a tiny size. However, when he tried with a lamb, it was reduced to a grotesque and useless mass of flesh. This failure frustrated him, and he became obsessed with perfecting his technology, leading to his ultimate downfall.