Secret Room riddle!

[RunRabbit]

I got stuck on the secret doors riddle on f1 next to the changing room a space away from the barrels on the right hallway. The door will persuade you too leave but eventually it will ask you if you like riddles, than it will give you a riddle, the riddle says...

I am not a bird, I am not a cat,
Nobody exept my murderer understood.
Now I am asking,
What is my biggest interest?

The answer is a 6 letter word, if you have any ideas, questions or the answer please respond.

[Akiha]

The answer is PUZZLE,because the riddle said puzzle is its biggest interest before it ask you this question.