Notable for the first appearance of a flesh colored canary, who would come to be known as Tweety.
Even in this initial appearance, Tweety reveals early on that his cute appearance masks a willingness to be merciless, even sadistic, towards anyone who threatens him. After slipping one of the cats a bomb which explodes (offscreen), the bird remarks, "Aw, da poor putty tat - he cwushed his widdow head!" Followed by a big grin. (This line was patterned after a catchphrase from a Red Skelton character, and would be used in other Warner cartoons, such as Easter Yeggs.)
The bird was unnamed in the short, although at the time the staff called it "Orson". [Wikipediia]