No one expected the house Hiccup Horrendous Haddock was sorted into.
He was from a Viking Clan after all. Viking's were honest, loyal, proud, brave, united, and loud, of course. They could swing hard and swig harder. Vikings were Gryffindors and Hufflepuffs and to be sorted into any other house proved you lacked True Vikings Spirit.
Vikings didn't go into Ravenclaw. That was a place for Greeks and scholars and those pompous Englishmen.
Vikings certainly didn't go into Slytherin. A Roman would be more suited for such a place of backward dealings, craftiness and lies.
Hiccup could handle the shock of his classmates (a Horrendous Haddock? In