A doubtful guest

"Every sunday it brooded and lay on the floor, Inconveniently close to the drawing-room door.
Now and then it would vanish for hours from the scene, But alas, be discovered inside a tureen.
It was subject to fits of bewildering wrath, During which it would hide all the towels from the bath.
In the night through the house it would aimlessly creep, In spite of the fact of its being asleep.
It would carry off objects of which it grew fond, And protect them by dropping them into the pond.
It came seventeen years ago -- and to this day It has shown no intention of going away." - Edward Gorey