Hagrid was wrongfully accused of housing the beast in the Chamber of Secrets and letting it loose to kill Myrtle Warren, who later became the ghost, Moaning Myrtle. In actuality, it was Tom Riddle, or Lord Voldemort, who set the Basilisk loose in the castle to kill muggle-born students. The spider that Hagrid kept, Aragog, never hurt anyone in the castle. Although Hagrid was expelled from Hogwarts, Professor Dumbledore trusted him and he was therefore given a job as a gamekeeper.