It' NOT Mark Evans, "sweetie," that answer was REALLY imaginative and REALLY wrong. JKR said that she laughed so hard she fell off her chair when she heard that "storge" title; and she would NEVER give that much information anyway. Also, Tom Riddle is named after his father, Tom Marvolo Riddle. Tom Riddle, Jr. killed Tom Marvolo Riddle and his parents, who are also Tom Riddle, Jr.'s grandparents. No one survived Avada Kedavra with the exception of Harry. We know that Colin's a muggle-born, not a half-blood because in the second book Lee Jordan is counting all those who have been petrified and he mentions that all of them are muggle-borns. I really don't think it's Hagrid, Seamus or Dean either because although they fit the half blood description, JKR said that at one point COS was title the Half Blood Prince. I mean, CoS definitely would not have worked as Harry Potter and Seamus Finnegan. Hagrid, Seamuse and Dean are not main characters in that book. Tom Riddle is though.