Similarity	Harry Potter	Tintin
Teenage boy who is an orphan	Harry	Tintin
White colored, loyal pet	Hedwig	Snowy
Quick-tempered follower	Ron	Captain Haddock
Absent-minded friend	Neville	Professor Calculus
Comical characters that look alike	Fred and George	Thomson and Thompson
Evil nemesis	Lord Voldemort	Rastapopulous
Enemy whose name is not said	He-who-must-not-be-named	He-who-unleashers-the-fire-of-heaven.
Friend thats a dog	Snuffles	Snowy
Character who has messy hair	Harry	Tintin
Knack for being in the right place at the right (or wrong) time *Thanks to Anthony	Harry	Tintin
Investigators *Thanks to Anthony	Harry	Tintin

If you've spotted another similarity, let us know!