Daffy Duck has always been my favorite Looney Tunes character, so I was happy to learn that director Chuck Jones' first go at Daffy was 1939's Daffy Duck and the Dinosaur. It's a fitting start, since Daffy is Warner Brothers' most famous extant theropod (back off, Tweety-lovers, just back off). Set in the stone age - "millions and billions and trillions of years before you people were even born," a title card informs us - it's one of a long line of Warner Brothers cartoons in which a prey animal protagonist outwits a hapless hunter. In this case, it's Casper Caveman. Not only does it seem to presage The Flintstones (Casper has a pet sauropod named "Fido," and his home has a very Bedrock feel), Casper's first attempt at killing Daffy may well have been the inspiration for the famous "bullet time" effect in The Matrix.
Daffy Duck and the Cave Man might have been a more accurate title, but I think Jones knew that dinosaurs were a better draw.