i hate to bring this up, but it wasn't the sorting hat that declared to harry that he was a wizard.
now if the caption had read, "yeh'd be great in slytherin, harry", that would be accurate.
(aside: i would have personally liked the books better if harry was sorted into slytherin, hermione into ravenclaw, ron into hufflepuff and the three still went on to become fast friends. it reinforces the message that we don't need to be alike to become pals.)
but the joke is inaccurate. might as well make it say, "i am a chelsea fc midfield legend wearing an orange dunce cap because i kicked the shit out of that pre-teen ballboy once".
heck, that's more accurate than the sorting hat adopting hagrid's tone.