You could take MDLVis (a model editor) extract the Troll Headhunter or Shadowhunter model with MPQ and then rename the flip animation of the model to 'Walk' in the model editor, that could do it ;D
Chaosy's solution would be using Trigger Editor, if I understood what he said.
No, what Zunariel has little to do with the animation backswing and all that. His suggestion requires editing a model, which you cannot do in World Editor. Chaosy's solution would be using Trigger Editor, if I understood what he said.
Correct.
Animation - Queue Your Unit's jump animation name animation