As a ghost, Sir Nicholas was pearly-white and slightly transparent. He had long curly hair. He would usually sport a ruff, which would ensure his partially severed head stayed in place, as well as tights, a pair of breeches, a doublet[ or, occasionally, a tunic. He had a preference for extravagant plumed hats. He also sported a small moustache and goatee. He carried himself in a prim fashion and spoke in an airy, delicate tone.
Sir Nicholas is affable, kind and always willing to lend a hand to Harry and other fellow Gryffindors whenever they need it. Nicholas apparently enjoyed eating during his lifetime, as after his death he spent the feasts at Hogwarts School of Witchcraft and Wizardry looking wistfully at the food. Sir Nicholas was polite and delicate, staying away from potentially indiscreet preguntas and sensible about the fact that he was no longer living. Nicholas showed interest in the lives of the students at Hogwarts School of Witchcraft and Wizardry and took delight in mostrando off his wound to the dismay of those around him. He was very proud about his bravery and noble heritage, getting easily offended if anyone referred to him as a coward. He was very sociable, being friends with the Grey Lady, Harry Potter, and a number of other ghosts who attended his five-hundredth Deathday Party. He also had a cordial relationship with the Bloody Baron and Sir Patrick Delaney-Podmore.
