Underdog's youth and origin remains unknown. Underdog's secret identity is Shoeshine Boy, a shoeshine boy by profession. As Underdog, he is romantically attracted to Sweet Polly Purebred, a news reporter who is also a dog. When he is needed to fight criminals, he ducks into a phone booth and changes his costume with such force that it usually destroys the booth, He uses his super energy pills to enhance his super powers which he keeps in a secret compartment in his ring. As Underdog he tends to speak in rhyme.
Underdog often fought alien menaces and criminals, as well as supervillains such as Simon Bar Sinister and Riff Raff.
Appearance
He wears a red jumpsuit with a white "U" on it that is clearly too big for him, and an oversized blue cape. He is tan with black ears. As Shoeshine Boy, he wears a pair of glasses.
Personality
Shoeshine Boy, Undersog's civilian identity, is "humble and loveable" in the words of the cartoon's narrator.
Powers and Abilities
Strength: Underdog's natural strength has been enhanced to levels far more greater than any normal human or canine.
Speed: Underdog can move and dash at speeds faster than any ordinary person or canine.
Durability: Underdog shows durability as he can withstand most hits and (self caused) crashes.
Sight: Underdog can see from far distances in excess of the capability of any normal dogs.
Hearing: Underdog can hear sounds coming in any direction from far distances.
Thunder Roar: Underdog can emit a powerful roar from his mouth which can shatter glass and other things.
Flight: Underdog is capable of flying at high velocities.
Appearances in other media
Film adaption
In the movie, he lives in a world more like our own, in which dogs and other animals are not anthropomorphic, and thus starts off as an ordinary police dog. After being put down by his fellow police canines and leaving. The beagle is abducted by Cad who takes him to Simon's lab. An accident occurs in the labs and Underdog's DNA is modified after he is exposed to DNA concoctions and chemicals. Underdog eventually escapes and is later chased by Riff Raff and his lackeys, then he is hit by a car but he is unharmed. He is taken home by Dan which names the beagle Shoeshine. All other events in the film leads downward as things change.
