Karl Rossum was the head of Cybertron and the man who created the super computer H.A.R.D.A.C.. He was once a mentor of Bruce Wayne in the areas of robotics and artificial inteligence. After H.A.R.D.A.C.'s destruction, Karl retired fully, then bought a farm on the outskirts of Gotham.
- Karl Rossum was voiced by William Sanderson
- 5 Appearances of Karl Rossum (DCAU)
- 1 Images featuring Karl Rossum (DCAU)
- Quotations by or about Karl Rossum (DCAU)
- Character Gallery: Karl Rossum (DCAU)