- " I'm an animal. Not a monster."
- —Point Laser Point
Sylvester made his first appearance, though only a silent cameo in The Jailbird and Jailbunny, during the song Blow My Stack, when Yosemite Sam was singing about not being able to count to ten at an anger management class.
In Devil Dog, Sylvester was chasing after Tweety, and just when he catches up to him, the Tasmanian Devil, as a twist to the usual antics, shows up and Tweety notices that Taz is behind Sylvester and says "I tawt I saw a Tasmanian Devil". Sylvester doesn't believe Tweety and grabs him. Taz is right behind Sylvester ready to eat them both. Sylvester notices and start running away from him. Tweety and Sylvester manage to escape Taz, by running to the kitchen, as he ate the table and Tweety flying away up the chimney with Sylvester on his legs. After Taz falls back to Daffy and Bugs, they both run back inside of Granny's mansion.
In Eligible Bachelors, Sylvester tries to catch Tweety with a golf club, but he landed in the chimney. He later appeared in the end when Tweety tells him that he fought in World War II and also tells him Tweety's gender.
One of his major appereances is in the episode Ridiculous Journey where him, Taz, and Tweety are seperated from their owners. They are moved all the way to Alaska and have to go on a long epic journey back home while at the same time avoiding from being caught by the hunter Blacque Jacque Shellacque.
- 103. Jailbird and Jailbunny (debut/Merrie Melodies)
- 108. Devil Dog
- 110. Eligible Bachelors
- 112. Double Date (Merrie Melodies)
- 113. To Bowl or Not to Bowl (Merrie Melodies)
- 114. Newspaper Thief (cameo in Merrie Melodies)
- 126. Point, Laser Point
- 210. A Christmas Carol (cameo)
- 211. We're In Big Truffle (cameo)
- 214. The Black Widow (cameo)
- 217. Gribbler's Quest (Merrie Melodies)
- 218. The Grand Old Duck of York (cameo)
- 219. Ridiculous Journey
- Even though Sylvester appeared in The Jailbird and Jailbunny, his first speaking role was in Devil Dog.
- Sylvester has evidently been given a style change since his last series appearance: He has gained a more slender, shorter body and his canine teeth have become more prominent and sharp, making him appear more like a housecat. In Season Two he resembles more like his classic-era counterpart.
- Sylvester originally thought Tweety was female, but was corrected on this in Eligible Bachelors.
- Like Daffy, he has a lisp when he speaks.
- Sylvester has both a mother and a brother, revealed in Point, Laser Point.
- Sylvester makes a very brief cameo in The Black Widow, where Lola releases him from a bag she was carrying. This is a reference to the saying, "letting the cat out of the bag", as a metaphor for telling the truth.
- In the video game, There Goes the Neighborhood, he could fly, roller skate, and shoot fake fists.
- Sylvester makes two cameos in The Grand Old Duck of York. The first one is at Granny's Mansion, when he is about to grab Tweety, but falls down due to Daffy's terrible piano playing. He later appears in the end, where Tweety, tired of hearing Daffy's piano playing, opens Sylvester's mouth and gets in.
- Jeff Bergman (US)
- Masashi Ebara (Japan)
- Alfonso Ramírez (Latin America)
- Roberto Pedicini (Italy)
- Michael Pan (Germany)
- Włodzimierz Press (Poland)
- Guy Rushiniak (Israel)
- Márcio Simões (Brazil)
- Tiago Retré (Portugal)
- Pusztaszeri Kornél (Hungary)
- Armand Calotă (Romania)