Batman: Shadow of the Bat Annual #1

The people of Gotham City and the Dark Knight alike are stunned by a series of savage, meaningless murders. When the otherworldly parasites descend upon Gotham High School to quench their insatiable needs, they find little resistance; but one of the parasites inadvertently creates the New Blood character Joe Public, and comes face to face with both Batman and this new hero who can absorb powers and strength from others.