There's no need to fear....
  3   4  4  4   4  -4    5    5  5
when criminals in this world appear
 -4  -4   -4   -4   5    -4   -3     3
And break the laws that they should fear
  3  4   4    4  -4   5  5   5
And frighten all who see or hear
 -4  5   5   5   -5   6   6   6
The cry goes up both far and near
 -6  7  7  7  67 67 67  7  7  7   67 67 67   
For Underdog! Underdog! Underdog! Underdog!
  7   -6   7  - 6    -7  6   -7  6
Speed of lightning, roar of thunder
  7   -6  7   -6  -7 6   -7  6
Fighting all who rob or plunder
 7 7  7   4  4  4
Underdog! Underdog!

when in this world the headlines read

of those whose hearts are filled with greed

who rob and steal from those who need

to right this wrong with blinding speed

goes Underdog! Underdog! Underdog! Underdog!
speed of lightning, roar of thunder

fighting all who rob or plunder

Underdog! Underdog!
http://www.youtube.com/watch?v=r8shn0v17JY