Answer:
Always in you, sometimes on you. If I surround you, I can kill you. What am I?
I begin and have no end and I end all that begins. What am I?
I'm at the head of an elephant and at the tail of a squirrel
I hop around and deliver eggs at Easter.
You can read me both ways I wear; One way it's a number reversed a snare.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.