Another smarty parrot character, voiced by Mel Blanc, is a scene stealer here.
Sylvester states that he's a cat, not an electrician. A variation of that line would become a signature phrase of Dr. Leonard McCoy in the Star Trek franchise, beginning with The Original Series (1966). McCoy famously states, "I'm a doctor, not a ...." on numerous occasions.
Although their facial features do bear a slight resemblance, kangaroos are marsupials, not rodents, which is the family mice belong to. And so do kangaroo rats, tiny desert critters that hop on their hind legs like kangaroos.