According to Bleacher Report, Harbaugh wore the blood of his player as war paint while at Stanford.
While this is certifiably crazy, it fits with what Michigan is looking for. After all, they already have Kyle "there will be blood" Kalis. I picture these two having pre-game blood brother sessions.
http://bleacherreport.com/articles/2309744-jim-harbaugh-reportedly-smear...