Eagle door knocker

The Eagle Door-Knocker of Ravenclaw Tower is a bronze, sentient, eagle-shaped knocker on the door to Ravenclaw Tower, and acts as the Tower's guardian in much the same way as the Fat Lady does for Gryffindor Tower. Unlike the Fat Lady however, the Knocker does not ask for a password, but asks a thought-provoking question that must be answered in order to enter. The questions differ constantly, asking puzzles and riddles. Such questions include

"Which came first; the Phoenix or the Flame?" and

"Where do Vanished Objects go?".

The questions typically have no straight forward answer, but require a level of reasoning or logic behind them that reflects the wisdom of the hopeful entrant to the tower. The Knocker often compliments successful entrants for their skillful logic, but tends to go quiet if the answer is wrong. The question will remain the same until it is answered. The knocker will not let anyone in who does not know the answer to its' question, though if someone else answers the question, one may enter with the victorious answerer.

History
The Eagle Door-Knocker was first seen during Harry Potter's infiltration of Hogwarts just before the Battle of Hogwarts. When Luna and he attempted to enter Ravenclaw Tower with the purpose of seeing a statue depicting Ravenclaw's lost Diadem, the Knocker waylaid them with a question to which Luna answered.

The Knocker moments later halted Amycus Carrow, who could not answer its question, and attempted to blast and bludgeon his way passed the door instead. The Knocker's question was answered by Minerva McGonagall, whom Carrow demanded open the door.

Description
The Knocker has a soft, musical voice, and seemingly pays little heed to any sort of dialogue other than that of answering its question, again a parallel to the Fat Lady.

Appearances
''*Harry Potter and the Deathly Hallows ''