Answer:
Stealthy as a shadow in the dead of night, cunning but affectionate if given a bite. Never owned but often loved. At my sport considered cruel, but that's because you never know me at all.
What does everyone know how to open but not how to close?
As soft as silk, as white as milk, as bitter as gall, a thick green wall, and a green coat covers me all.
Today he is there to trip you up. And he will torture you tomorrow. Yet he is also there to ease the pain, when you are lost in grief and sorrow.
What is neither inside the house nor outside the house but a necessity for any home?
Special abilities and brightly colored underwear are all you need to be one of these.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?