Answer:
I can be swallowed But I can also swallow you.
I'm really blue but when you see me I'm red. You don't see me too often. I'm there for you if you're hurt.
Who makes it, has no need of it. Who buys it, has no use for it. Who uses it, can't see it. What is it?
I can be found in water but never wet
What do you get when you cross a pig with a karate expert?
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.