Answer:
I know a word of letters three. Add two, and fewer there will be!
I am free for the taking. Through all of your life, though given but once at birth. I am less than nothing in weight, but will fell the strongest of you if held.
You’ll have me at night and if you remove the first letter I denote the top, such as on a train
A leathery snake, with a stinging bite. I'll stay coiled up, unless I must fight.
What do you throw out when you need it but put away when you don’t?
When is it bad luck to see a black cat?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?