Who was the cartoon girlfriend of the dog that changed into his costume in the phone booth?

Question

What was that dogs name? What was he saying when he flew up in the air?

Answer 1

your talking about underdog! he says "theres no need to fear
underdog is here!"

and his girlfreind was polly purebread!

Answer 2

I loved Underdog!!! And Sweet Polly Purebred, too.