Yakko is the oldest Warner sibling. He is said to be 14 from an interview with the creator of the series Tom Ruguer. He is most likely the cheekiest of the three siblings. Yakko, as his name implies, is the most talkative and quick-witted of the Warner siblings. He's also the tallest as well as oldest.
- Yakko's catchphrase is Hellooo nurse!
(It is also said by Wakko)
- Yakko appeared as an inflatable balloon display on top of the water tower in Burbank in real life, this was in promotion of the show before it was released. However, when Bob Daley, who ran the studio at the time, saw the balloon, he thought that for some reason, Mickey Mouse was sitting on top of the tower and he requested it to be removed. It was removed but not before Paul Rugg took a photo of the balloon.
- He has been seen to be able to play the piano, as seen when he is with Beethoven as well as during the Great Wakkoratti concerts, yet all three siblings are good at playing instruments.