Victim: Walker pleaded guilty to wounding with intent, attempting wounding with intent and possessing a bladed article after the attack on Emma (pictured) and Leah.
Ryan Walker, 19, wears glasses and has short dark hair, just like actor Daniel Radcliffe who plays the young wizard in the hit film series.
A court heard how after two girls called Walker Harry Potter, he snapped, stabbing one of them in the face so hard that the blade of his vegetable knife broke.
Walker then pushed the other girl's head into a nearby fence and shouted: 'Die, die'.
He claimed he launched the ferocious attacks in Southampton, Hampshire, after being goaded repeatedly by the girls who called him Potter.
Southampton Crown Court heard how Walker returned to his family flat after shopping for his mother and he had to pass 15-year-old Emma Keeble and 16-year-old Leah Pearce sitting on the stairs.
One of the girls touched his shopping bag before verbally abusing him and telling him he resembled Harry Potter.
Outraged Walker saw red, rushed to his flat before coming back downstairs with a milk bottle full of water and threw it over the girls.
He then went back into the flat and re-emerged with a vegetable knife before walking to a local park - knowing the girls would follow him.
Walker then lost his temper, stabbing Leah in the face, who then started bleeding profusely.
Bloodied: Emma Keeble, 15, pictured before her head was pushed into a fence by Walker, and afterwards.
After his arrest he made a full confession, describing his actions as 'monstrous'.
He pleaded guilty to wounding with intent, attempting wounding with intent and possessing a bladed article.
Ryan Walker, 19, was jailed after stabbing a girl in the face and smashing another's head against a fence because they called him Harry Potter.
She said: 'He finally lost it. He flipped and attacked them in this most horrific way, not justifiable, but I hope they can now see where it came from.'
Passing sentence, Judge Peter Ralls QC, said the girls may have been rude, but there was no justification for what Walker did to them.
'It was deliberate and planned,' he said. 'It was a sustained attack in which you used the knife as a weapon and your foot as a weapon.'
Walker was sentenced to a jail term of four and a half years.
After the hearing, Leah's mum Claire Pearce, said: 'The injury has left a scar on Leah's face that will be there for years.
'I don't think the sentence was enough for what he did. He admitted he flipped and it was the final straw.
'I think he is a dangerous man given he flipped like that and attacked the girls.
'I feel sorry for the next person that calls him a name.'
Now they'll remember, for the rest of their lives and every time they look into a mirror to do their make-up, to not be bullies.