Son of Oakley the tree troll. Mellisandre revealed this to Dickon (Team 6 of Series 4) in an exchange of information - he had told her the Roman name for Colchester (or so she thought). When Dickon encountered Oakley shortly afterward, his mention of Little Acorn convinced Oakley of the dungeoneer's good intentions. Little Acorn was never seen on Knightmare.
