Bio: Hav-Rogg was the only known child of Zey-Rogg and the only known grandchild of Yon-Rogg, though there may be others running around (assuming that they exist and that they survived both the NegaBomb and the subsequent Shi'ar occupation of Hala). Very little is known of his history before the fall of the old Kree Empire. Presumably he was attending a Kree military academy before Hala fell. He is/was (I guesstimate) about 5-7 years old when last seen.
Hav was rescued by Legacy from being squashed by a piece of falling debris (which was falling because Legacy blew up a couple of Shi'ar Skimmercrafts overhead, but that's another matter).
He later talked to Genis about what happened to him when he returned to Calculex after talking to the Kree Resistance Front (read the summary up above for what happened during that part of the issue) and learned the fate of his father after the fight.