 Frank was described as 'cuddly' and 'fuzzy' and with a chubby, babyish face in "The Mark of Athena", but in "The House of Hades", after summoning the blessing of Mars to defeat a hoard of enemies, he transforms.He is then described as being taller, more muscular, and without all his childhood fat.Though now built like a professional football player, he is still as sensitive as before, and is embarrassed at his new appearance at first.