Unlike most other Looney Tunes animals who are usually “animals with human traits” to varying degrees, Porky Pig kind of has this Donald Duck like portrayal in terms of anthropomorphism level to him. Like Donald Duck, he is pantsless and has a body shape roughly like his no anthropomorphic counterpart. Also like Donald Duck, he is frequently portrayed like a “human in an animal suit.”
Porky Pig is also the only character cast with Sylvester who can’t talk to (“Kitty Kornered” is the exception to the rule). Sylvester is shown to be able to talk to Daffy Duck, Tweety, Speedy Gonzales, Foghorn Leghorn, and other animals. He is even able to talk to humans like Elmer Fudd and Granny (when disguised as a bellboy in “Canary Row”). Sylvester is also shown to be unable to talk to a non-anthropomorphic orange pig in “Too Hop to Handle,” so he may just be unable to talk to pigs despite being able to talk to other animals, including humans.
The Animal Talk trope lets animals with the exception of humans talk to and understand each other*, but Sylvester is able to talk to humans and unable to talk to hogs. Is there something about swine that makes Sylvester mute toward them?
The Looney Tunes, Tiny Toon Adventures, Animaniacs, and Pinky and The Brain universe, by in large, runs on the Talking Animal trope, in which animals can talk to and be understood by humans, so when some cartoons or episodes appear to run on the Animal Talk trope (like many Rita and Runt and Goodfeathers segments), it’s just for that cartoon or episode or the segment type just plays that way and is not applicable to the whole universe. Plus, some cartoons and episodes shows the characters as toons, animated actors, and toon actors in-universe. Those type of cartoons are Talking Animal in nature.
* The Animal Talk trope would make more sense if it included humans among the animals that are able to talk to and understand each other because humans are animals.
Fictional Animal Tropes and Representation 